The return-path is used to process bounces from your emails and is set in the email header. It defines how and where bounced emails will be processed. The return-path can also be referred to as a bounce address or a reverse path, and is an SMTP address that is separate from your sending address.
Senders can use the return-path address to specify a certain email address to send bounce notifications too, instead of clogging up your from or reply-to address.
Having a return-path in place can even help your email deliverability! It's worth checking if your email marketing campaigns have a return-path set.
Why The Return-Path Is Important
Setting a return-path is important for all senders, but especially for those email marketers sending bulk email. Email bounces are a fact of life even for the cleanest email lists, and the return-path gives those bounces a defined place to go to, instead of clogging up your sending inbox.
If you have a return-path setup and are getting lots of bounce notifications, consider cleaning your email list with a validation tool.
Adding a return-path to your emails can also give you credibility in the eyes of ISP's like Gmail, Yahoo, and Hotmail. Inbox providers can use the return-path as part of their filtering process, so including one with your email campaigns can aid your deliverability and boost your sender score. As split inboxes become more popular, like Gmail's default Inbox, Promotions, and Updates tabs, improving your inbox placement with positive signals can be the difference-maker in where you land.
The email domain in your return-path should match the domain in your from field as well. It's all about sending a consistent message to inbox providers that you're not attempting anything sketchy.
How Return-Path Works
Mailbox providers validate your emails in many different ways to verify your identity as a sender. One of the common ways is through SPF and DKIM lookups on your domain. DMARC, an email authentication process that was created to prevent phishing, works specifically with the return-path. It checks to see if the sender's name and the return-path match up.
Once that confirmation is complete you'll have sent a strong signal to inbox providers that your emails are legit, but Setting the return-path isn't going to magically fix any deliverability issues you have. Many email service providers, or esp's, let you set a custom return path, but many will automatically set one for you.
If you are having deliverability trouble, consider exploring Mailgun's Deliverability Services. It's our comprehensive email program that matches you with a Mailgun Deliverability Expert to make a custom deliverability solution tailored to your specific needs. Learn more about deliverability services.