Subject Lines: Rules + Best Practices

Ah, the ever-elusive subject line. Think of it as your headline before your headline.

After all, in a statistic from Convince & Convert with Jay Baer, “69% of email recipients report email as based solely on the subject line.”

That’s my focus.

You need to keep things clean and safe. Don’t get reported before people even have a chance to open your email!

There are many things to consider when thinking about subject lines.

“What am I trying to communicate?”

“How do I get them to open it?”

“How closely should it relate?”

Well, if you’re Joseph Sugarman, author of the Adweek Copywriting Handbook, you would tell yourself, “Oh, it doesn’t need to relate at all! It just needs to get their attention and keep them reading.” He had a very strict policy in copywriting that it doesn’t matter what your headlines say, it just needs to be big and lead the reader to the next thing.

I’m more of the school of thought that it should relate and be interesting.
Your subject line, to maximize opens, should follow 3 key rules:

Be personal

Be short

Be clear

In SEO, a key component Google looks for to help your blog rank is clarity in alt text (the text that describes pictures on your page) and meta text (the text that describes your page to their search engine). Why? Because they understand how important it is to be clear, concise, and easy to understand.

No one wants to go into your website or email with one expectation and then get completely thrown.

You’re more likely to convert if your reader gets what they expect and then some.

You’re less likely to convert if your reader expects one thing and then feels fooled when they open it.

Case Study Moment:

I worked with a direct marketing specialist who once had a 65% open rate on a list of 100,000+ because one day he tested the subject line: “Oops…”

65% open rate!
1.5% click thru rate…

The readers felt fooled. And this is not a criticism of his work, though I’m sure he’d appreciate me promoting his successes, because he tested and tested and learned there actually is middle ground to be had.

Subject Line Types:

Yes, you’ll argue with me. “Aren’t there more types?! What about questions or humorous?!”

My argument back to you: “They all fall under the following three subject line types. Also, calm down.”

Plus, this is from years of testing and studying. Trust me.

Curiosity.

The curiosity-based subject line is probably the most effective. After all, it did kill the cat. (Not sure what I meant by that, but I’m not mad at it either.)
In an email from HuntAKiller.com, after about 3 days of not converting with them, I got this email: “I don’t like this, but I’ll do it anyway…”

Yes, I clicked. They offered me a discount against their will. The subject set me up in many ways:

I felt empowered because they were conceding. It felt personal because I felt like I was being talked to. It made me very curious to what they were gonna do that they didn’t want to.

Curiosity-based emails are good for questions, including names, etc., such as: “Cup of coffee, Mike?”

I assume a coffee wholesaler or coffee shop with email list would want to send that one. If you’re taking this course and want to send a personalized email to your coffee shop’s email list…There you go. Don’t use “Mike” though, use their first name. We’ll talk about how soon.

Fear.

“Today only”

“Don’t miss out!”

“Buy this, or else.”

Time = fear. Your customers or readers feel like they’re going to miss out will get them to act faster.

An effective email from Digital Marketer had a subject line that read “Your 7-figure plan goes bye-bye at midnight…”

A bit long, yes, and I would have tried to include the subscribers first name, but it has personality, it’s clear, and it has a sense of urgency.

Straight Forward.

The old “I’m your friend I promise” trick.

The straight forward subject line is simple, clear, friendly, as if you know the person.

We’ve all heard about President Barack Obama’s legendarily personable subject lines. My favorite?

“Hey”

That’s it. It’s in multiple articles and blogs online. Because it worked.
Why does it work? Because it feels like a friend sent it. And as a liberal myself, I like to think a friend did send it. 🙂

Other examples of Straight Forward subject lines:

“Hey man, did you see that?”

“I have some files for you”

“Remember that one time”

These are all characterized by lower case characters and most often, a lack of punctuation unless its a question.

Rules for Subject Lines:

Some basic rules for you to follow when writing subject lines.

Keep it UNDER 35 characters. Mobile apps usually cut your subject line off around 35-50 characters. If you’re including your subscribers first name, be sure to get the main point of the subject line in under 35 characters so they can at least get an inkling it’s personalized.

Stay away from NUMBERS. “Free” is a good word to use, but SPAM filters love to pick up on numbers and percentages. Typically, there are ways around them, but no need to get tangled in that web if you can avoid. The rule here is to keep your emails in their inbox.

Always TEST your subject lines. Always test and resend the winners to non-openers. More on that later, but write that down. ALWAYS TEST. A/B/C, even D, test that subject line.

Personalization:

I talk a lot about “personalizing” emails. But what does that mean?

ESPs will often have a field that, if included in your email, will include your subscriber’s first name in the subject line (and body too) of the email. All you have to do is include it in the field.

In ConvertKit, an ESP for creators and entrepreneurs, it looks something like this:

Subject line field in ConvertKit

This will only work if you got their first name when you onboarded them.

That’s why on my list builders, I always ask for their first name. Of if you’ve effectively gotten their permission when they checked out, your ecommerce company should have plenty of data you can merge into your email.
Other ways to personalize?

eCommerce companies, pay attention: You can merge your customer’s location data with your ESP, I promise. Just make sure the integration is advanced enough to take it. If not, you can contact your ESP and they will give you the tools to import a properly formatted CSV.

Now you can put “Los Angeles” or “Atlanta” or even target emails by zip code! True story.

Preview Text

What is preview text?

This:

Examples of Preview Text in emails

For Petco, the preview text is: “Celebrate National Cuddle Up Day with…”

For BottleKeeper: “BottleKeeper 2.0s are back. Only for a limited time…”

Why does this matter? It’s EXTRA subject line space!

Not every app will display it, such as mobile, but when it does, it gives you extra space.

Some ESPs have a specific field for your preview text that will hide it from your email body. Others do not and will require you to get clever and integrate it into the top of your email.

I prefer the latter, it keeps things fun. For example, in ConvertKit, I can include preview text like so…

Where to input/how to deal with preview text when creating a campaign.

See how I made it smaller than the rest of the email, to make it clear it’s part of the pre-amble, and out of the way?

And if you want to avoid the body of your email creeping into your pre-header, use Litmus’ subject line preview text hack that helps you get rid of all that extra text with a simple line of code and easy instructions. I use it and so should you. The Litmus hack will also hide your preview text completely.

Check it out here.

The Importance of Integration

My first job as an Email Marketing Manager was a mess. They had a strange, proprietary Ecommerce System with developers in, I want to say, Bratislava or Bulgaria or somewhere whose time difference makes it impossible to get anything done…

“What’s integration?” Dude, it’s saved my life.

Here’s a little backstory: After my first job, which was comfy, paid okay, but took care of me for six years, I felt like it was time to move on. After all, I had 6 years under my belt, 5 of which in digital marketing and copywriting. For a few years, I was in love with email so I figured, “How hard could it be to get an email marketing job somewhere?”

It wasn’t hard. What was hard was what came after.

It turns out that there are a lot of people and companies who have no idea what they’re doing. Big surprise, huh? Whether they didn’t consult their teams to make sure the tools they use can communicate or just devalued marketing so much that they went for cheap programs that made other peoples’ jobs harder.

My first job as an Email Marketing Manager was a mess. They had a strange, proprietary Ecommerce System with developers in, I want to say, Bratislava or Bulgaria or somewhere whose time difference makes it impossible to get anything done. Not only that, their Email Service Provider was a system that had very few native integrations, was very developer-reliant (not good when they’re all the way in Slovakia), and their CRM was all done in spreadsheets, so nothing could be automated.

It became very clear incredibly quickly that the first thing any CRM pro needs is integration. And that goes beyond what you might assume.

How? Well, you got a bunch of things to look for:

If you’re in retail and ecommerce: Does the Retail POS (or, Point-of-Sale system) actually automatically send customer data back to us? Is there a Loyalty system that hooks up right into our CRM or ESP?

Does the ecommerce platform automatically sync product and customer data with your marketing systems?

Basic rule of thumb here: The less you need a developer, the better. They need to work on the website and functionality, apps, et cetera. Don’t make them waste their time on email or CRM marketing where they don’t absolutely have to.

If you know quite a bit about digital marketing already, you may be wondering:

“But Andrew, dude, don’t transactional emails need to be deployed by a developer?”

No. There are ESPs like Klaviyo that, if you’re ecomm store is synced up, will let you build post-purchase journeys that include all of that. And if it integrates with your shipping service, digital product delivery service, or you have a CRM that integrates that will let you do all of that, guess what?

You can do it all yourself.

So, don’t be fooled! Integration across all systems is the name of the game.

We’ll talk about it another time, but a strong CRM system that integrates with your ESP and other systems can be key in bringing this all together.

What is CAN-SPAM Law?

This might be a little dry & boring. Well, boring, but good, because I’m about to save you thousands in government fines.

$40,654, to be exact.

“Wait. What!? Why?”

Well, it all starts with a little organization called the Federal Trade Commission, or, the FTC. They have worked to keep businesses compliant via the wild west of email when they enacted the CAN-SPAM Act. CAN-SPAM is an acronym for “Controlling the Assault of Non-Solicited Pornography And Marketing Act of 2003.” Let’s break it down and go over why this matters. “Assault”: Ever look at your spam folder? Ever look at how many you get in a day? Well, in the days before spam was filtered out and a law was in place, you’d get all of those sent relentlessly by the minute if you happened to visit the wrong site or activate the wrong cookie. That’s “assault” to a T. “NON-Solicited”: This is what I’ve been bugging you about ALL ALONG. Imagine you didn’t voluntarily hop aboard an email list and you suddenly got emails you didn’t want. Yeah, you’d be pissed. This law is in place to tell businesses if these emails are not solicited, they are gonna go straight to the SPAM folder! “Pornography”: Okay. “Marketing”: This is where you fall under, I imagine. Marketing encompasses any email that is coming from a commercial place for commercial purposes. Think of it this way: Even though a blogger may not make money via direct transaction and it’s free for you to read, they are onboarding you for commercial purposes because they need to keep your viewership around, because they need the sponsorship dollars, I assume. Therefore, commercial encompasses anyone sending you email because they need your engagement for more than simply sending you a photo of their cat. According to the FTC, “following the law isn’t complicated.” And if you don’t follow the law, you’re gonna be paying that $40,654 fine.

Yeah. So, don’t break the law because you’ll pay out the wazoo. But since it “isn’t complicated,” they also lay out the following ways you can make sure you’re doing it. Without further adieu, courtesy of the FTC, their 7 requirements for following CAN-SPAM: Don’t use false or misleading header information. Your “From,” “To,” “Reply-To,” and routing information – including the originating domain name and email address – must be accurate and identify the person or business who initiated the message.

Don’t use deceptive subject lines. The subject line must accurately reflect the content of the message.

Identify the message as an ad. The law gives you a lot of leeway in how to do this, but you must disclose clearly and conspicuously that your message is an advertisement.

Tell recipients where you’re located. Your message must include your valid physical postal address. This can be your current street address, a post office box you’ve registered with the U.S. Postal Service, or a private mailbox you’ve registered with a commercial mail receiving agency established under Postal Service regulations.

Tell recipients how to opt out of receiving future email from you. Your message must include a clear and conspicuous explanation of how the recipient can opt out of getting email from you in the future. Craft the notice in a way that’s easy for an ordinary person to recognize, read, and understand. Creative use of type size, color, and location can improve clarity. Give a return email address or another easy Internet-based way to allow people to communicate their choice to you. You may create a menu to allow a recipient to opt out of certain types of messages, but you must include the option to stop all commercial messages from you. Make sure your spam filter doesn’t block these opt-out requests.

Honor opt-out requests promptly. Any opt-out mechanism you offer must be able to process opt-out requests for at least 30 days after you send your message. You must honor a recipient’s opt-out request within 10 business days. You can’t charge a fee, require the recipient to give you any personally identifying information beyond an email address, or make the recipient take any step other than sending a reply email or visiting a single page on an Internet website as a condition for honoring an opt-out request. Once people have told you they don’t want to receive more messages from you, you can’t sell or transfer their email addresses, even in the form of a mailing list. The only exception is that you may transfer the addresses to a company you’ve hired to help you comply with the CAN-SPAM Act.

Monitor what others are doing on your behalf. The law makes clear that even if you hire another company to handle your email marketing, you can’t contract away your legal responsibility to comply with the law. Both the company whose product is promoted in the message and the company that actually sends the message may be held legally responsible.

I CANNOT stress how important this is. It’s kind of crazy how important this. CAN-SPAM separates the jerks from the nice people. It keeps businesses accountable, like I said before. Also, it really helps keep your list healthy, engaged, and trusting you. If you need more information on CAN-SPAM law, all you need to do is check out the FTC’s site on CAN-SPAM: https://www.ftc.gov/tips-advice/business-center/guidance/can-spam-act-compliance-guide-business Enjoy.

What’s ISP Blacklisting?

Blacklisting: When your emails break rules and affect an ISP’s customers in such a way that they have to ban your emails.

You’ve heard of the infamous Hollywood Blacklist? (If not, look it up.) Well, there’s another kind of Blacklist you need to look out for.

Story time: I was working at a direct marketing company for about six months. In addition to shoddy management, questionable work practices, and an essentially broken marketing system, there was a glaring issue in email. One morning, the deliverability dropped to 64%. In case you don’t understand if that’s bad or not, because “Hey, it’s more than half. right?” Would you be okay with a 64% in a class in high school? That’s a solid D, but hey, at least it’s not an F.

There were a number of factors that played into this. We’ll get more into it another time but there was a clear issue with how customers were being acquired and an issue with how the rest of the company was run.

Side-note: A marketing team is not the be-all-end-all. What I mean is, you can only do so much to get customers to buy, keep buying, get in the door, whatever. At the end of the day, Operations, Sales, Accounting, and Customer Service need to be working to get to your same exact goal. If they aren’t, then everyone needs to be kept in check.

Anyway, that was my little rant, but it played into my issue. When customers who didn’t necessarily opt in (We were culling them from previous sales) also could not get proper help from customer service or even access the website properly, everyone got hit.

Customer service got numerous complaints and even more than that, we got hit with Spam complaints. All this to say, our domain was blacklisted. There are more factors than merely Spam complaints.

Here are the ways you can get Blacklisted from Google, Yahoo, Outlook, all of that…

Spam complaints. We talked about that. People either forgot they opted into your newsletter (or you weren’t clear but we’ll talk about that another time), or you added them to your list without their consent so they’ll mark you as Spam. Enough of these and you. Are. Outta here.

Unengagement. If your email list is 500,000 strong, good for you. But if only 6% are opening, that’s not good and there’s no reason to keep a lot of these people around. If an ISP looks at your emails and notices a vast majority of everyone getting them isn’t opening them, they will determine that you are not a valid domain to get emails from and after enough of this tomfoolery, you will get blacklisted. First, you’ll get greylisted, but we’ll discuss that another time.

Bad emails. This is why you need double opt-in! If any Joe Schmoe can type in their email and you don’t have a double opt-in enabled for them to confirm their subscription, guess what? Could be wrong. In fact, most people are not great at typing. Then you’ll have invalid emails on your list that bounce back to you courtesy of the evil Mailer Daemon. Next thing you know, Gmail is gonna “Hey, this domain keeps trying to email people with bad emails, they must be bad themselves or don’t know what they’re doing, let’s keep them away.” And boom, blacklist.

There you have it. You wanted to know what blacklisting was and now you know.

Fun, right?

Email Copywriting: A Simple Guide

Neville Medhora, famed copywriter & teacher, describes copywriting like so: “Re-arranging words to sell things better.” And he’s right. All you’re doing is writing an effective letter in order to sell your item more effectively.

Neville Medhora, famed copywriter & teacher, describes copywriting like so: “Re-arranging words to sell things better.”

And he’s right. All you’re doing is writing an effective letter in order to sell your item more effectively.

Let’s take a look at this email from the incredible subscription box site, HuntAKiller.com

That’s it, that is the whole of the email.

So, what did they get right? And perhaps, more importantly, what did they do wrong?

STRENGTHS:

Personability:

The personability of the copy is very strong. HuntAKiller.com is a subscription box murder mystery game that requires you to solve a murder through Mindhunter-esque correspondence with a fake serial killer. Killer concept (pun definitely intended), right?

Right.

But they knew their brand needed a voice, so they took on what feels like a cold, collected tone that befits the game.

Lesson?

Find your voice and weave it into the copy.

Vertical Writing:

Yes, it may “lengthen” your email, but a copy trick in copywriting is vertical writing.

Notice how they don’t save a line for more than a sentence at a time?

And it kept you reading line after line?

That’s the trick.

At times, it’s short.

Other times, they find ways to make it long, because variety is intoxicating to the eye.

Lesson?

Vertical writing keeps the eyes moving.

Vary the length, make it tall, get the conversion.

Emphasis:

I know, I probably use too many bolds in this here lesson, but that’s okay, because this is essentially a robust article with video. When it comes to email, however, save your emphasis for when it matters.

In this email, they saved emphasis for two key things:

COUPON CODE & CTA.

With the coupon code, it’s important to make sure it stands out in any email.

Why?

I used to work in customer service. Too, too often did the company I work for forget to emphasize or make clear coupon codes.

Then customers call and complain that they couldn’t find the code or what they thought was the code did not work.

Then they start opening your emails less. Even worse, they could complain to their ISP (Gmail, Yahoo, whatever) and boom, your brand is blacklisted from Gmail. Then no one gets your emails. Then your company fails. Then you die.

Okay, that last part is overkill, but possible.

As for the Call-to-Action (or, CTA):

We will go over CTAs soon, but to touch on it for a second here, I just want to say that they were smart in saving the link for the end. The call to action is a clear link that entices you with urgency and fear of missing out.

“Click here to use it, while it lasts.”

It tells you to click, builds in an end time the email already alluded to, and it’s not overdone — it’s only in there once!

This CTA is Copywriting 101: Clear. Enticing.

Lesson?

Save your emphasis for when it counts! Don’t blow your wad on a billion bolded words and 6 links. You need to aim for specificity here. Speaking of which, this email also excels at…

Specificity:

Too often, too-big-to-fail companies like Walmart and Target will send mass email blasts that are general and sale-oriented.

Guess what? They don’t care because they don’t have to, they are Walmart! They are Target.

But you need to care, because you’re the David to the Goliath and your slingshot is email.

So, how do you defeat them?

Not on a grand scale, no, but battle by battle.

By being specific.

We’ll touch on “Segmentation” in “DELIVER” but specific emails aimed at specific people is key.

In the HuntAKiller.com email, it has a very specific and small, but effective aim, it is a retargeted email because I gave them my email and had yet to actually buy their service.

This isn’t a big ol’ promotion for the entire site, it’s just one for me because I’m in a segment of potential customers yet to convert.

That kind of specificity can drive your conversion rates sky high.

Lesson?

Simple. Be specific.

WEAKNESSES:

The email is not defined by weakness as much as its abundant potential.

This email could have used…

Images.

We’ll go over this soon, but a simple image would have helped.

Better yet, a company like this could leverage its marketing department to get a video made, potentially by a shadowy serial killer who wants to say something to you.

If they then put up a screenshot of the video with a fake play button over it with the CTA to “Watch this killer’s message to you,” that would probably drive conversions way, way up. Video player images are HUGE converters.

In general, images used responsibly are great. Some emails don’t need any more than one, like this.

Button

I know, I said the CTA they had was “Copywriting 101” but I, personally, like an HTML button.

Again, we’ll touch on this later, but an HTML button is a real eye catcher.

Therefore, it could have gone more like:

Click below to use it, while it lasts…

BEGIN >

It’s not much, but a clickable HTML button goes a long, long way.

More on Copywriting:

I didn’t read Joseph Sugarman’s AdWeek Copywriting Handbook for nothing.

Because of that, I know there is no one better to describe the tenets of copywriting than Joseph Sugarman himself.

While, for email marketing, I don’t necessarily agree with his personal philosophy that the headline is there to merely get the reader to the next part, regardless of the relation to the content.

That being said, the following “17 Axioms of Copywriting” stand apart from any personal philosophy and instead provide clear, concise tenets for copywriting.

Without further adieu, Joseph Sugarman’s 17 Axioms of Copywriting, courtesy of Fat Atom:

Copywriting is a mental process, the successful execution of which reflects the sum total of all your experiences, your specific knowledge and your ability to mentally process that information and transfer it onto a sheet of paper for the purpose of selling a product or service.

Copywriting defined. Take everything you’ve ever learned about your subject and turn it into a well-formatted story with the aim to converse with the reader and sell.

All the elements in an advertisement are primarily designed to do one thing only: get you to read the first sentence of the copy.

In my eyes, you want it to all be cohesive, but that’s neither here nor there. The main point here is, entice them with your subject line to get them to read your first line…

The sole purpose of the first sentence in an advertisement is to get you to read a second sentence.

Your ad layout and the first few paragraphs must create the buying environment most conducive to the sale of your product or service.

Get the reader to say yes and harmonize with your accurate and truthful statements while reading your copy.

Your readers should be so compelled to read your copy that they cannot stop reading until they read all of it as if sliding down a slippery slide.

When trying to solve problems, don’t assume constraints that aren’t really there.

Keep the copy interesting and the reader interested through the power of curiosity.

Never sell a product or service. Always sell a concept.

The incubation process is the power of your subconscious mind to use all your knowledge and experiences to solve a specific problem, and its efficiency is dictated by time, creative orientation, environment and ego.

Copy should be long enough to cause the reader to take the action you request.

Every communication should be a personal one, from the writer to the recipient, regardless of the medium used.

The ideas presented in your copy should flow in a logical fashion (Down), anticipating your prospects questions and answering them as if the questions were asked face to face.

In the editing process, you refine your copy to express exactly what you want to express with the fewest words.

Why use 10 words when you can use 4: Be clear and concise.

The more the mind must work to reach a conclusion successfully, the more positive, enjoyable or stimulating the experience.

Selling a cure is a lot easier than selling a preventative unless the preventative is perceived as a cure or the curative aspects of the preventative are emphasized.

Telling a story can effectively sell your product, create the environment or get the reader well into your copy as you create an emotional bonding with your prospect.

That’s it for copywriting. Any longer and my fingers may fall off.

What are SPF, DKIM + DMARC?

SPF, DKIM, DMARC. Three acronyms that, to any newcomer to email marketing, are daunting and feel almost impossible to understand. Luckily for you, I’ve done the research, talked the talk and walked the walk. Here, I want to lay it all out in one place for ya. So, you’re welcome.

SPF

No, not the level of your sunscreen. SPF is short for “Sender Policy Framework”, a DNS (Domain Name System… Holy shit, enough with the acronyms, Internet) entry that contains the server names that are a-okay to send mail for a specific domain.
Meaning, you (or your IT person) have to add your server name to your Domain Name System so that ISPs see these emails are coming from a legitimate source. According to End Point, “[Because] SPF is a DNS entry can also [be] considered a way to enforce the fact that the list is authoritative for the domain, since the owners/administrators are the only people allowed to add/change that main domain zone.”
This also means that because only you or your administrators have the power to change your SPF entry, it signals to everyone else that you must be real, “After all, only their top people can change it.”
If only they knew you are probably working out of a garage trying to get your start-up off the ground. But no worries, we all start somewhere.

DKIM

Just another one of those terms that you’ve definitely heard but probably never even bothered to ask about. What does DKIM mean?
DomainKeys Identified Mail. That grammatical nightmare of a name is a method for content verification. You or your IT person has to add a DKIM Key entry to your DNS so that when every message you send goes out, the DKIM Key is attached to the message. This communicates to ISPs that the content in your email has not changed since it left your server (thanks, SPF) and made it’s way to someone else’s.
The fact that it’s a private Key code adds that level of legitimacy needed to be considered trustworthy.

DMARC

Let’s just get it over with, because it’s a doozy:
Domain-based Message Authentication, Reporting & Conformance. Say that 10 times fast, do 20 jumping jacks, and finish reading this. Without DMARC, SPF and DKIM don’t necessarily work. DMARC, again according to the fine people at End Point, states “a clear policy which should be used about both the aforementioned tools and allows to set an address which can be used to send reports about the mail messages statistics gathered by receivers against the specific domain.”
In fact, let’s take more from End Point (Why even have this blog? Because, I’m funnier than they are) and look at how each of these work:
How SPF Works: Upon receipt, the HELLO message and the sender address are fetched by the receiving mail server (Your recipient).
The receiving mail server then runs an TXT DNS query against the claimed domain SPF entry.
The SPF entry data is then used to verify the sender server.
And in case the check fails, a rejection message is given to the sender server (You).
How DKIM Works: When sending an outgoing message, the last server within the domain infrastructure checks against its internal settings if the domain used in the “From:” header is included in its “signing table”. If not, the process stops here. And ya dead.
[In layman’s terms, let’s say I send an email from “andrew@crmcomplete.com”. Once I send it, the final server that I plugged into my DNS, using the DKIM key, will verify that, indeed, my message was both SENT FROM and ACTUALLY CONTAINS “crmcomplete.com”. That means it matches what I told my DNS it should. If it can’t find that, then you or anyone else will not see my email.]
If the domain used in the “From” header is included in the “Signing Table,” however, then…
A new header, called “DKIM-Signature”, is added to the mail message by using the private part of the key on the message content.
From here on the message main content cannot be modified otherwise the DKIM header won’t match anymore.
Upon reception, the receiving server will make a TXT DNS query to retrieve the key used in the DKIM-Signature field.
The DKIM header check result can be then used when deciding if a message is fraudulent or trustworthy. If it passes said “Fraud Check”, your message is deemed from legitimate source.
How DMARC Works: Upon reception, the receiving mail server {Your recipient’s} checks if there is any existing DMARC policy published in the domain used by the SPF and/or DKIM checks. There should/better be.
If one or both the SPF and DKIM checks succeed while still being aligned with the policy set by DMARC, then the check is considered successful, otherwise it’s set as failed.
If the check fails, based on the action published by the DMARC policy, different actions are taken. That means there are degrees to which you might get dinged.
For example, if you passed both SPF and DKIM checks, but for some reason there’s still an error pertaining to the DMARC policy, you could be sent to Spam, held back from just a few recipients, grey or blacklisted. You just never know, so best practice is just make doubly sure your DMARC policy is set up and ready to go.
Boom. If anyone asks you, just repeat all of that verbatim.
[Thanks to endpoint.com for that information. While I spruced it up and made it a little more relatable, the bulk of that info came from them.]
Oh, and one more thing:
You don’t technically need to set up SPF, DKIM, or DMARC in any way. These are best practices put in place to ensure deliverability and the safety of your audience. While without them, they could get you in trouble with the FTC, this is not a standard government regulated practice. These are tools we as marketers can use to make life much, much easier.