Crafting email messages to protect deliverability

The world of email deliverability is constant, evolving, and currently utilizes things like subscriber engagement and domain reputation more strongly in inbox versus spam-filtering decisions. With that said, there are some content-related items that can affect your inbox placement depending on these and other factors involved.

Since deliverability is about having as many positive signals as possible, here are some tips around strengthening your content to strengthen your deliverability.

Files like PDFs, Google Docs, and others have been highly abused by malicious actors so that providers, B2C and B2B, are very wary of them. Sometimes you can get away with including them but if there ever comes a time where those spam filters are unsure due to other not-so-great practices and they see one of these files, the provider will err on the side of caution and filter you.

Shared link shorteners like (though not their custom-domain link shorteners), etc. have also been highly abused due to their ability to hide almost anything behind them, which is why spam filters err on the side of caution with these too. Typing out a link in the body text of an email is also a problem because the tracking links behind the typed URL will look different. Always make sure that links are hyperlinked behind images, buttons, or non-URL text to avoid this issue.

The domains referenced in the links contained in an email are also being checked for reputation, beyond just the domain in the sending address. If the link or domains being referenced have a poor reputation or are known to be associated with spammers, your message can be related to theirs and experience issues accordingly.

Image and content file size

The file size of your message can cause different experiences depending on the size and provider you’re sending to. Images and GIFs can be a large contributor so make sure you are using compressed image files when able, including making a single image copy of any image collages you want to include in your content. A good rule of thumb is to keep your final message size, images and all, below 2 MB.

Image to text ratio

Having an image and link alone is suspicious due to malicious actors’ activities. A general suggestion in the industry, then, is to keep the image to text ratio to approximately 40:60. To do this, it is good to try to have around 3 or more lines of text for every image and to make sure you add relevant alt-text to images for accessibility and functionality purposes.

Misrepresented or violent content

While this is not widely affecting, misrepresented or violent content is a factor that can be looked for, depending on the mailbox provider you are sending to.

Subject lines and content, text content and links — these elements need to be aligned content-wise, both to improve human experience with your messages (which majorly affects deliverability) and system checks, to not be or appear suspicious. Misrepresented content is very low in impact but worth noting for a healthy relationship with subscribers, at the very least.

Furthermore, some providers do evaluate content and the types of words being used, but more to do with violent or suspiciously problematic content, especially content centered around violence and the public encouragement of it.

Using Ortto email message templates

The Ortto email message templates found in the email campaign wizard (as well as journeys and playbooks) are adjustable, which can affect your experience so please remember to keep the preceding advice on this page in mind when making your changes.

The below guidance is high-level, general advice and is in no way intended to be restrictive to how you use the email message templates.

Ortto’s Use cases email templates are designed to help you place the focus on your content while supporting a healthy image-to-text ratio. These templates are ideal for the various themes and content-approaches they are named for. In general, they are great for many marketing campaign content frameworks. Remember, with larger templates like these, keep image file size down by compressing images and try to not use some of the highly-abused links as advised above.

Ortto’s Simple templates, specifically the 1 column full width1:2 column full width, and 1:3 column full width templates, are a simplified breakdown of image-to-text ratio. These should be utilized for messages concerning highly expected and specifically actionable content, such as surveys, welcome information, and account confirmation.

The Plain text and Simple text templates are great for very particular, necessary circumstances. A majority of use-cases for these templates would be for communications that require no action on the recipient’s end and are specifically for informational purposes, such as alerts and confirmation messages.

Learn more about creating email campaigns under Creating an email campaign.