Emails can go to Spam, Promotions, and other folders for all kinds of reasons.
Many of the email clients subscribers use have extremely sophisticated filtering systems. While those systems are advanced, they won’t always be 100% accurate on where to send certain emails.
Even with great content, a good sending reputation, and following the best practices for deliverability, a subscriber could still have filtering preferences set up in their email account that they may not realize are affecting the deliverability of your emails.
This is why we suggest telling your subscribers to allowlist your sending address.
This tells your subscriber's email provider that they want your emails and expect to see them in their primary inbox.
If your email address has been allowlisted, the email client should send your message to the inbox and bypass any spam filtering.
Example of an allowlisting request
When you ask your subscriber to allowlist your email you can simply say:
“Hi! Thank you for letting me know you aren’t receiving my emails. To help with this, would you mind allowlisting/safelisting my sending email in your account? That way your email provider will know you’d like to receive my email directly to your primary inbox!”
Each email box provider has different steps that subscribers need to follow in order to "allow emails". It's best to suggest the subscriber look up the process for their specific email provider. There can be different terms used as well such as "add to contacts, add as a safe sender, add to safe list".