How to stay out of the Spam folder

7.56% of emails in the U.S. hit spam filters (Source: Return Path).

I could start this lesson by explaining SPF, DKIM, Sender ID records, SpamAssassin… But I won’t.

Instead, I’ll give you a quick explanation of how and why your email can end up in the spam folder and then we’ll put all the focus on the things you have to do (or not) to avoid it.

This is one of those quick tips type of lesson, so I’ll go ahead and drop a ton of information on you, but we’ll do it in bite size points. 😉

One thing I want to mention, I know we made a reference to the “Spam folder,” but I hope you understand that all this stuff we’re covering here, really affect much more than that. Getting a campaign flagged as spam is one thing, but having a subscriber block you, or an ISP, having bad reputation, or even being black listed, that stuff can really take down your entire email marketing and damage your business.

Alright, now we can get started!

How does an email end up in the spam folder?

Almost every single email account in the world use spam filters. From a user point of view, I’m sure you wouldn’t want to have an account without one.

Spam filters analyze all components of a message to identify the presence of spam characteristics. When something is detected, your email is automatically sent to the spam folder and chances are your subscriber will never see it.

Why you should care

You’d agree with me that all spammers should be punished, right? But the problem is that sometimes legitimate messages are marked as spam because of an honest mistake.

Have you ever found an email from someone you know in the spam folder? I just found my sister in there, or you can even find one of your clients…

Marked as spam

This is why it’s very important that you care about all this, we both know you’re not as spammer, but that doesn’t mean you won’t get flagged as one. And, what are the chances your subscribers will take the time to dig you out of the spam folder, right?

So, these are the best practices to avoid triggering a spam filter:

1) 2-Step Opt-in process

Yes, we’ve covered this but I still need to mention it here because this is one of the most important things you can do for the health of your campaigns.

Focus on prevention.

2) Purchased lists

From the moment you enrolled in this course, I have to assume you understand this, but it should be present in a list of tips to avoid the spam folder.

The whole point of email marketing is that a person has a genuine interest in what you do, and for that reason, she has given you permission to email her. Without that, this does not work.

Maybe you’ve heard about scraping email addresses from Facebook users, even if they are your own Fans, that is not only a bad practice, but it can also get you banned. I mention this because I had a client that did this without knowing it was wrong, out of the advice from a very shady marketer.

3) Ask to get whitelisted

I mentioned before that this should be your goal right after the signup process has been completed. We covered this in the previous lesson.

4) Images

The use of images is one of the main triggers of spam filters. Here are a few best practices to follow carefully:

  • Too many images in a campaign can be interpreted as spam
  • Always add alt text to all your images
  • Don’t replace text with an image. Text should be text

Image alt text

5) Subject line

I know I told you to write subject lines in a more friendly manner, but that doesn’t mean you’ll go crazy about it, besides I know what kind of friends you have! 🙂

  • Excessive use of exclamation marks!!!!!
  • Use of symbols

And always, always spell check your subject lines. If you need help with this, consider using an application like Grammarly.

6) Bounces

Your email list has a percentage of undeliverable address, this is why you see “Bounces” when you send a campaign. When you keep sending emails to the same accounts, your reputation as a sender is damaged and the chances of being flagged as a spammer increase and it can cause your IP address to be blacklisted.

We have a lesson ahead in this section to cover how to clean your list.



7) Embeds and attachments

Never embed forms in the body of your email or add attachments as you do on your personal account.

Instead, send people to a landing page.

8) Opt-out link

Always include your “Unsubscribe” link. This goes on the footer of your email but it should be visible and clear.

Opt-out link

9) Free email addresses

Free email addresses such as Gmail, Hotmail or Yahoo tend to be judged as spam. Instead, use a verified domain.

In my case, although I use Gmail to manage my account, the domain is This also helps the recipient identify you (we talked about this before). My advice is to always use the same domain of your website.

Verified domain

10) Links

Links in email campaigns are very sensitive. Make sure you follow these points:

  • Always check that your links are not broken
  • Don’t add the actual URL in the body of your email, instead add a hyperlink to a line of text
  • Don’t use short links such as

Don't use URLs

11) This is not spam

Remember how Facebook started penalizing posts that actively ask for Likes? The same thing happens with email, telling your subscribers that “this is not spam” is a clear indication of spam.

12) Spam trigger words

Words, as you know, can be very powerful to help you get people take action in your campaign, but they can also play against you.

Certain words, both in your subject line and in the body, can easily make spam filters go crazy.

Here are a few words to avoid:

  1. amazing
  2. cancel at any time
  3. check or money order
  4. click here
  5. congratulations
  6. dear friend
  7. e-mail marketing
  8. for only ($)
  9. free (including toll-free)
  10. great offer
  11. guarantee
  12. increase sales
  13. order now
  14. promise you
  15. risk free
  16. special promotion
  17. this is not spam
  18. to be removed
  19. unsubscribe
  20. winner

Hubspot published a list of words categorized by segment, I think it’s one of the most accurate ones out there. You should bookmark it.

Words that trigger spam filters

In the next lesson, I’ll show you how to check your campaigns for spam before sending them out.

  • I noticed that one of the spam trigger phrases listed here (for subject line or body) is “Click Here”. But, in another lesson that same phrase was listed as the best/top performer for getting people to click links/buttons. That appears like a contradiction, but maybe when used in a button it doesn’t show up as text? Can you clarify? Thanks.

    • I think the lesson you’re referring to is where I say that, besides the actual CTA button, there is a command in text to take action on the button, like “click here to learn more.” That’s just to help the CTA, but it’s not the actual CTA.

      • I’m on my cell phone now so I’m sorry I can’t remember exactly which lessons I’m referring to. But in the two lessons I am referring to, click here is listed in a graph as a top performing call to action phrase… (the statistic was something like 30% more click throughs occurred with the use of that phrase than with the other four phrases it was being compared to), This would imply that the words click here would be in the body of the email. In this lesson its saying that click here could actually trigger spam. ? Hope that makes sense. Thanks!

  • Telling people “this is not spam” (not that i could see myself using that phrase, but…), is this referring to subject line text or anywhere in the email? thx.

    • The example that comes to mind is when someone is telling you about a business ideas and she says “this is not network marketing.” There are 2 possibilities after that statement, either it IS or it’s very close to it.

      If it’s clear that your content is not spam, you shouldn’t have to say something like that.

  • Let’s say i’ve made innocent mistakes in the past which i’ve now realized. I’m wondering how the “my reputation as an emailer” works? Where can i find “how i’m doing” in that regard. Is it sort of like a credit score? Who/what body keeps track of this? How can i find out if i have been labeled as a spammer, or if i’ve been blacklisted by ISP’s etc. How can this type of thing be tracked, monitored, understood or improved upon by me – ‘the sender’. Also has the sensitivity to this sort of ‘flagging’ changed? Does it continuously evolve / change? Thx!