10 Best Practices for 100% Email Deliverability

Most marketers and founders assume that crafting compelling emails with attention-grabbing subject lines and engaging copy is the key to strong email outreach. Sorry not sorry: The key to successful email marketing isn’t the content you create, it’s email deliverability.


Because if your emails aren’t reaching their intended recipients, it doesn’t matter how engaging the subject line and how impactful the content is. If your emails are going to spam, no one will see them, so all of that work you put into creating the perfect email is wasted.

The key to successful email outreach is deliverability.

And this is where most marketers fail. The truth is, many marketers come from a content background (myself included), and many of those marketers never take the time to fully understand email deliverability. This is probably due to the fact that it’s ridiculously confusing–you have to understand how different servers and ESPs operate, and how to properly warm up domains and IPs.

There is also a ton of information online about how to achieve effective email outreach, and much of it is contradictory and confusing. I know, because I spent years in the trenches figuring this all out. Email deliverability is definitely tricky, but once you master it, you have a superpower–you can deliver thousands of emails to inboxes daily.

Just think about that: A marketer who understands email deliverability can get your message straight into the inboxes of your ideal customers, at the rate of thousands of contacts per day…and can do this forever.

Sound valuable to you?

In this article, we’ll dive into 10 best practices needed to master email deliverability. I’m sharing some of my pro-tips here, get that copy/paste ready!

1. Start with a Quality Email List

Ok this first one should go without saying, but I’m starting off with it because it’s literally the first step in the process (don’t worry, there will be some more tactical ‘in the weeds’ action items later on).

Overlooking a strong email list is a recipe for deliverability disaster.

While you can purchase lists online for relatively cheap, remember that you must then run these lists through email-checkers like Neverbounce to ensure that the emails are verified. You don’t want to get hundreds or thousands of bounces–that will get you blacklisted and send you straight to spam.

I recommend using platforms like Apollo, ZoomInfo or Grata to obtain verified (green) emails. I’ve had success relying on these platforms (they all use the same verification procedures, so it doesn’t matter which you use, though ZoomInfo and Grata have added features, but are also way more expensive).

2. Regularly Clean Your List

Here’s where the rubber starts to meet the road. Purchasing email lists is one thing, but keeping them clean requires ongoing work, which is tedious and manual. We’re talking about removing bounced emails and ‘no longer employed here’ auto-responses. Definitely not the most fun way to spend your time!

But a clean list is a must–it not only improves deliverability, but also enhances engagement metrics, as this is the only way to ensure you are reaching an audience that is genuinely interested in your content.

3. Always Market from a Subdomain

This is critical. NEVER perform cold outreach from your root domain.

For example, say you run XYZ company, and your domain is xyz.com. You absolutely unequivocally DO NOT want to email prospects from xyz.com!

Why not? Because if your prospects begin marking your emails as spam, this will damage the reputation of your root domain, making it difficult for you to send non-marketing emails. That means emails you send internally, or to vendors or customers, could get flagged as spam.

I once joined a company where the previous marketer sent emails from the root domain. It was pure hell getting the domain back to health, and took several months. Never again! Always use a subdomain to send marketing emails. For example: info.xyz.com

4. Warm Up!

Never start your cold outreach by sending thousands of emails–or even hundreds of emails. You must warm your domain and IP first!

‘Warming up’ means sending to small numbers of people at first, and slowly building up to thousands per day. It should take you anywhere from 4-6 weeks to properly warm to 1,000 contacts per day.

Also, do not send a campaign during the warmup phase. Campaigns are when contacts receive multiple emails from you. Never do this in the warmup period.

You only want to send contacts a single email at a time during warmup. Why? Because when people get one cold email, they never bother to send it to spam. But when people receive 3, 4 or 5 emails in succession, some of them will mark as spam. And getting marked as spam is the worst thing that can happen for your deliverability–especially in the first few months of your cold outreach, when servers are still figuring out if you are legit.

So only send a single email per contact in the warmup phase. You’re welcome.

5. The ‘From’ Name and Signature Matter

Yes they do. Do NOT send marketing emails from ‘team@’ or ‘marketing@’. You want to do everything in your power to signal to the recipient servers that you are a human being, not a bot, and that includes having a real name in the ‘From’ address and signature.

For example, my emails come from [email protected]. And my signature has my real name, my title, my email address and my website. Just like a real human person would! Definitely not some AI bot over here–

6. Actually Write Your Subject Lines and Content–Don’t Use AI

I know, I know–why write anything when Chat GPT can do it for you? But the truth is, AI just isn’t there yet when it comes to non-spammy content. Servers can read and detect this stuff, and they’re very adept at understanding human vs. AI language.

That’s not to say you can’t use AI entirely. You can use it to get a rough draft of copy out, just make sure you run through it and ‘humanize’ it, before sending it out. The few minutes it takes to do that will be well worth it, trust me.

7. Use the A/B Test Feature to Create Variations of Your Emails

Most people don’t know about this little trick. I always create 4-5 variations of every email I send out. Not to actually A/B test them–I’m not trying to nail down the one that works best. Nope. I do it because I don’t want to send thousands of the exact same email.

Think about it: you are trying to convince recipient servers you are a human being. Repeatedly sending the exact same email out to thousands of contacts per day is a surefire way to get locked in email prison (otherwise known as Spam).

Instead, create variations of your email using the A/B test feature, and dump a few hundred recipients into each version. The more versions the better–that said, it can be tough to vary your email up 10 different ways!

8. Optimize for Mobile

An obvious one, but often overlooked. Ensure that your emails are mobile-friendly by using responsive design. And always check how they look on mobile by sending yourself a test email first. Most recipients will check your email on their phone, so you want to be sure it looks good on mobile.

Also, don’t use images if you can help it, because they slow the load time, especially on mobile. And speaking of images…

9. Avoid Images Altogether!

There really is no need. Cold outreach is about making a connection with the prospect, and not seeming like a salesman or bot. Images are pretty sales-y.

Maybe you have a reason for including an image–ok, I’m not going to tell you that you absolutely can’t. But just understand that this is NOT a best practice. An A+ cold email will have no images, because they slow the load time and are considered spammy. If you have to include one image, it might not be the end of the world (provided you’ve properly warmed your domain and IP). Just really use this sparingly, if at all.

10. Always Include an Unsubscribe Link

I know what you’re thinking: why should I include an unsubscribe link–wouldn’t contacts unsubscribing hurt my deliverability?

The answer is yes, but only a little. Having large numbers of unsubs isn’t great, but it’s not terrible either. What is terrible is large numbers of spam complaints. That will ruin your rep in a heartbeat. And if contacts can’t easily unsubscribe, they will get frustrated and mark you as spam.

This is why it’s best practice to not only include an unsub link, but make it prominent. Don’t hide it way down at the bottom in super tiny text. Make it clear that users can easily unsubscribe, and you’re cool with that. Because you are cool with it–if people don’t want your emails, they SHOULD opt out. Never emailing them is a good thing, because your engagement rates will improve if you stop emailing everyone who wants to unsubscribe.

So look at that unsub link as your friend, not your necessary evil. It is saving you from getting marked as spam, and it is allowing disinterested contacts to opt out of your outreach.

In Conclusion

Mastering email deliverability isn’t rocket science–but it’s not 2+2=4 either.

There is A LOT that goes into this. I could honestly write 100 best practices off the top of my head. Don’t include links in your warmup phase, monitor your analytics and iterate based on bounce rate, etc.

There are levels to this game.

That is why, if you’re going to embark on cold outreach, it’s best to do so with a professional who understands best practices and can confidently get you the deliverability you need, so you land in inboxes, not in spam.

Yes, hiring someone (like me) comes with a cost. But the ROI will be worth it. Plus, once you’re set up for success, you’ll have a cold outreach engine that is working, and you can simply rinse and repeat for years and years–continuously generating more leads and revenue.

Sound too good to be true? Set up a time to chat, and I’ll prove my system works.