Improving Mail Deliverability: Keeping Marketing Emails Out of the Spam Folder

Improving Mail Deliverability: Keeping Marketing Emails Out of the Spam Folder

Email spam filters were made for a reason – to keep those unwanted emails out of your inbox.

Some filters perform better than others, though they all do a pretty good job. But, what happens when a legitimate business owner such as yourself has accumulated a lengthy email list from your subscribers, and you find that your marketing emails are ending up in their spam folder? This is one of the most frustrating problems email marketers face.


Spam filters perform their job based on certain criteria that they find in incoming emails. Knowing and understanding what these are will help you to prevent your marketing emails from ending up in the spam folder.


Tips on How to Improve and Optimize Email Deliverability

– Most spam filters look to see how many messages you are sending at one time. If you have a large list, you don’t want to send out more than a couple thousand per hour. Some email programs will allow you to schedule outgoing mail to be sent out at intervals specified by the sender.

– Avoid large attachments and executable file types. If you’re using images, keep them reasonably small and stick with .JPG, .GIF or .PNG, as they are the more trustworthy formats. Executable files such as .EXE or .ZIP should be totally avoided, as they will surely be flagged as spam.

– Don’t use deceptive subject lines or header information.

– If you are going to include graphics or images with your emails, try to include at least two lines of text for each image, in order to keep a good text-to-image ratio. Also, make sure not to send image-only emails.

– When using HTML, make sure it’s well formed. Also, include a text version of your email, which will benefit recipients who can’t view HTML.

– Keep a clean email list and update it often. If you find bounce-backs from undeliverable emails due to disabled accounts or full inboxes after sending out your email, remove them from your list. Virtually all email providers’ spam filters penalize your domain or IP with a high spam score if they see that you are sending emails to a high amount of bad email accounts.

– We have all seen spam, so avoid looking and sounding like it. Don’t use a lot of coloured fonts or exclamation points. Don’t use all capitals. Don’t overuse the word “free”. Also, don’t ever use words like porn, Viagra, or drugs, as these keywords are the pioneers of spam.


As a last and final step, send a test email to each of the big email providers like Gmail, Yahoo, MSN and AOL. If the test results in most of your emails are going to the junk folder, then you’ll have to make some changes and figure out what flagged your email as spam. Free spam checking services such as are also available.

Rob Pacinelli

Roberto Pacinelli is the VP of The Best Media and Senior Digital Marketing Strategist with a career in digital marketing spanning over 19 years. Roberto and The Best Media have helped thousands of small, medium and large businesses succeed online across Canada, USA and the world with many business owners recognizing Roberto and his team as their Key to Success in helping their businesses earn millions of dollars as a result. Call Roberto Pacinelli at 416 253 0934 or email him at