Email Deliverability Guide Part 4: Unsubscribe Handling, Receipt Engagement And Whitelisting

This Email Deliverability Best Practices Guide was originally published by the team at Mailgun. Mailgun is an easy-to-use, API-based email deliverability tool for developers which Rackspace acquired in August 2012. 

In Part 1, we gave an overview of how to maintain a good reputation with email service providers (ESPs) and how to host your email infrastructure if you want to manage email deliverability yourself. Part 2 discussed how IP addresses, sending volume, DNS and Authentication affect deliverability. In Part 3, we looked at how to maintain email lists, bounce handling and spam complaints. Today, we’ll discuss how to handle unsubscribes when they happen, recipient engagement and whitelisting.

Unsubscribe Handling

It is important to give your recipients the ability to unsubscribe from emails. First, it is required by the CAN-Spam Act. Second, if you don’t give them this option, they are more likely to click on the spam complaint button, which will cause more harm than allowing them to unsubscribe. Finally, many ESPs look for unsubscribe links and are more likely to filter your email if they don’t have them.

Mailgun customers have the ability to include an unsubscribe link automatically in your emails. We give you the ability to link the unsubscribe to a certain campaign, mailing list or make the request global to your domain. You can access this data through the Control Panel, API or via Webhooks. In addition, we will automatically stop sending to email addresses that have unsubscribed. It is possible to remove addresses from the flagged list in your Control Panel or through the API.

Recipient Engagement

In addition to processing bounces, complaints and unsubscribes, ESPs measure your reputation through the engagement of your recipients. If recipients are opening, forwarding and replying to your emails, it will improve your reputation. This is what makes ”do-not-reply” emails so offensive. At many ESPs, it is also helpful if recipients add your email address to their address books.

So it’s important that you write emails that your users engage with.  Obviously, this is good for business, but it also means that more of your email will get through ESP filters, which creates a virtuous cycle.

For Mailgun customers, you can track opens and link clicks with our Tracking and Campaign functionality (see our User Manual for more information). You are free to create as many campaigns as you want and use them simultaneously for A/B testing. In addition, Mailgun is built to receive and parse emails efficiently. So there is no excuse to not allow your recipients to reply to your emails. Email is not a billboard – it is a conversant technology.

Whitelists and Other Deliverability Tools

While not required, it is a good idea to sign up for whitelists where available. A whitelist (that’s the opposite of blacklist) is like having your email pre-cleared by an ESP. Not all ESPs have them and they usually require some history of sending before they will allow you to sign up. Also, most of them require that you be on a dedicated IP address. Word to the Wise provides a list of whitelists along with feedback loops.

In addition to the whitelists provided by the ESPs, Return Path has a certification program that whitelists you at many of the major ESPs. In addition, the certification enables images to be displayed by default at many ESPs (which is not usually the case). Return Path also provides seed lists (so you can test if your email is being spam filtered) and campaign preview (to see how your emails are being rendered across ESPs and test for spammy content). You can read more about the benefits on Return Path’s website.

For Mailgun customers with dedicated IP addresses, we can register you for whitelists. Also, you can set up a test inbox and use our spam filtering technology to provide a “spamicity” score for your outgoing emails, which lets you see their propensity for being filtered. Finally, all accounts with dedicated IP addresses are qualified for Return Path certification. Our technology has been pre-vetted so the only remaining step is for them to monitor your sending in order to certify you.

That’s it for this time!  In our final installment, we’ll discuss how to write emails that don’t get flagged as spam.


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