Avoiding Email Inbox Spam Filters

Email Marketing takes all possible actions to ensure your email gets through to your readers' inboxes. The one aspect that is up to you, however, is your content!

We don't have a comprehensive list of all the words and phrases you should avoid, because spam filters are very sophisticated nowadays! For example, many filters are customized towards habits of each particular user, instead of following blanket rules about what is and what is not spam. The context of your words and phrases is taken into account, more and more -- so avoiding seeming spammy is actually your best bet.

To avoid filters, you want to think about how your content is presented as a whole, rather than avoiding specific keywords. The best tips are not black and white. We know this is less satisfying in the short term, but our advice below is more effective in getting you to inbox -- now, and in the long run.

To Avoid Spam Filters, Look at your Email Content and Ask these Questions:

Will email filters and subscribers immediately recognize me?

If the answer is anything but a solid Yes!, you need to address this, immediately. Domain names, from addresses, and templates, or styles should stay very clear from email to email. And they should match your Website, and other communications -- including wherever these folks signed up for your list. This helps both filters and humans establish who you are. Your branding creates a track record of trust. If people were receptive to your emails in the past, consistent branding will get you better filtering results.
Have I made a great first impression?

If you haven't sent emails to your list yet, or the emails you sent weren't well-received, send only to your most recent and engaged subscribers. Take extra care to ensure the content is something your subscribers will be excited about reading or interacting with.
Is my email focused on charming my subscribers, rather than "blasting" 'em?

Remind readers of your existing relationship, and then build on that rapport. Write emails in a conversational style, similar to how you'd address a friend or colleague. Hard-sell tactics are annoying to people, and they invite complaints and suspicion with both filters and humans. That said, don't go out of your way to hide that you're sending a bulk email. Spam filters can tell if you're sending the same piece of mail to many people, anyway. And people don't mind receiving a bulk email, if they've signed up for it -- it's the tone and content inside that they care about.

Here are a few content tips, to keep in mind:

The subject title is particularly sensitive to these suggestions.
- In general, it's a good idea to avoid any phrases like: Free, Instant, Double your money, Sex, XXX, Win, Cash, Bonus, Membership, Free Offer, Call Now, Rates, $$$’s, Success, etc.
- Excessive use of CAPS LOCK can cause issues, as well. NO ONE LIKES TO BE YELLED AT!
- Minimize your use of punctuation. !!!'s and ???'s can be troublesome. Keep your campaign conversational, rather than the hard-sell EXTRA!!!! BUY NOW!!! style.
- Pricing and $$$ signs are especially important. Including the pricing in your campaign can trigger a spam filter. An effective way to get around this and increase web traffic is to describe the special offer and link to your website. An image with the pricing is also effective.
- Subject Lines are really important. Really putting thought into your subject titles will not only help you avoid spam filters, but your view rates are likely to improve, as well!
Am I sending to contacts that not only signed up for my emails, but want this particular content?

It can take as little as one determined and unhappy person to cause filtering problems. So if you're not sure if a certain list will want an email, it's probably better to leave them out entirely.
Does it look like I'm hiding something?

Image-only emails are often filtered to spam. Sending an email that is only comprised of images makes spam filters think you're trying to hid something from them. They aren't able to scan the content of images, so they have no clue what your email is about. Make sure that you are clear about the intent of the message with text content, too! With text content in addition to image content, filters can more easily understand your identity and your intention.

Link shorteners are abused heavily in emails to hide malware and other not-so-great stuff, so don't use those, either.

What if I'm having problems, and I'm already doing all of the above?

Try a different subject line or take out the links to websites (that you don't have full control over) in the email and send a test. We recommend you create a test list and send to a few different email accounts before sending to your entire list.