Deliverability tips for content

This article outlines some common ways that your content will affect your deliverability with the current trends in email deliverability.

General Rules

  • Use a recognizable sender name or from address
    Try to keep this consistent.
  • Encourage recipients to forward and reply to your emails, and remind them to add your email address to their contact book
    All of these actions have very positive metrics on your sender reputation.
  • Generally anything that our Spam Check flags is a good idea to change
    If it says “Make lots of money!” for example, this means you have included language that resembles a "get rich quick scheme" and is likely to be flagged as spam. If you have questions about these rules specifically, feel free to contact us for help.
  • Make it easy for recipients to unsubscribe
    The larger your unsubscribe font is, the better. This will help you avoid spam complaints which are 100x worse than an unsubscribe. Never try to hide your unsubscribe link—this will hurt your deliverability.
  • Don't fret too much about spammy words like “free” and “100%”
    These don't typically have a big impact on deliverability. You should generally try to avoid them, but if your overall sending practices are good (good engaged lists) then you don't have to be too picky about your word choice—common sense is the best guide here.

Specific no-no's

  • Don't use link shorteners (eg, bitly)
    These are used heavily by spammers to mask their link destinations and are always listed on major blocklists.
  • Don't use a full HTTP link as the forward-facing text of a hyperlink
    For example, this is what you want to avoid in your emails:

Using a full hyperlink as the forward facing part of a hyperlink looks suspicious, because there's no guarantee it actually redirects to that URL—it could just as easily redirect to another, malicious page. Instead, use simple text such as “Click Here” and embed your link into that text. You can also include a button in your communication that links to your page.

  • Don't try to use an HTML form or any Javascript in your email
  • Don't include attachments

Common misconceptions

  • Text-to-image ratio is very important
     This is outdated advice. Our Spam Checker will even present a warning on the Campaign Summary page if your email seems to have a skewed text-to-image ratio. This warning is more of a suggestion and typically does not have an effect on deliverability. Just be sure you don't send a pure image email. There are still contacts who have images turned off by default in their email service provider.
  • Plain text ensures better deliverability
    This isn't true anymore. Most email filters care more about your sending history than the format used to send the message (HTML versus plain text).
  • The “sent on behalf of” or ”via” header hurts deliverability
    It does not affect your deliverability. You are more than welcome to remove it, but there is no negative effect on deliverability by leaving it as is.


The more personalized you can make your email using conditional content and personalization tags, the better. Most email service providers can identify language that is targeted to the recipient. This especially applies to using personalization in a subject line or From email address. The more you can target your message to the recipient, the more likely the inbox is to think that message is important and belongs in the inbox.

If you've just migrated from another service and would like more information on maintaining good deliverability, check out this guide

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