Optimize your emails for deliverability

Business Benefits

Build a good sender’s reputation, resulting in better inbox placement.


Warm up your IP address by sending small volumes each day over 4-6 weeks according to your email marketing platform’s IP warm-up protocol.

  • Every email marketing platform will have a slightly different IP warm-up routine and many platforms will have a tool to do this automatically for you.
  • Check your sender score or reputation or IP reputation using Sender Score or Google Postmaster tools. If you have a poor sender score, you may need to create a new IP address/domain and begin a warming protocol.

Remove unengaged subscribers and hard bounces to ensure you are sending valuable content to your segments and maintain good list suppression practices.

Poor open rates (under 12%) or high unsubscribe rates (above 0.2%) indicate you need to clean and segment your list. If you consistently have poor open rates, your deliverability will suffer and likewise if your unsubscribe rates are too high.

Create emails that are free from spam words, formatted correctly, include an unsubscribe link, and are not too image heavy.

  • Overusing spam words will get your emails put into a user’s junk folder. Check your junk folder and read some email to get an idea of words and phrases to avoid. For example, Hubspot has an excellent resource on which spam words to avoid.
  • Overusing images or sending emails that have a high image to text ratio can be detrimental to your deliverability. Spammers send emails that are 100% image base to get around spam word filters. The ideal ratio is 60% text to 40% imagery*.* However, text to image ratio is less important than other factors such as reputation and spam word avoidance.

Implement a sender policy framework by collecting all IP addresses that you’d like to authorize to send your emails from.

Access your DNS control panel and add the SPF records into the TXT type record, and include a tag for your email service provider.

Set up double opt-in or confirmed opt-in for your new subscribers to confirm the validity of the signup.

Your email marketing platform allows you to enable this for all new signups. While this practice can reduce the amount of new subscribers you get as it is an extra step, it will go a long way to maintaining a good sender reputation and good list health.

Maintain a consistent From name and From email address when sending, so users recognize who the email is from.

Constantly changing these can result in poor open rates, as users are more likely to open emails from recognized sources.

Analyze your sending frequency and adjust according to the results, reducing frequency if open or unsubscribe rates become an issue.

A good starting point is to begin with one email a week to a particular segment and slowly increase the frequency while monitoring open rates and other KPIs for deliverability. Your goal is to keep open rates above 12% (as a minimum) and unsubscribe rates below 0.2%. The more segmentation you have, the better your emails will perform, as you will be sending relevant content and offers.

A/B test your subject lines, using at least 3 variants to drive higher open rates - make a note of what works to replicate it for future emails.

Subject lines are key to maintaining a good sender reputation, and the most important factor when it comes to deliverability is user action. If your open rates are low due to poor subject lines then your deliverability will suffer.

Provide links to the content in the email, instead of sending attachments to your list and validate your CSS to correct errors which will impact deliverability.

Attachments almost always trigger spam filters when bulk emailing. Jigsaw is an excellent resource to validate your CSS and will help you avoid ending up in a user’s junk box for poorly formatted emails.