Most modern anti-spam measures rely on the concept of "reputation". When you send an email, the recipient's email servers will take into account the reputation of the sender. Depending on that reputation (and other factors), it may choose to accept your email (yay!), reject it, or route it to the spam folder. Therefore, it is important to the success of your email campaigns that you maintain a good email reputation.
Maintaining a Good Email Reputation
The number one thing you can do to maintain a positive email reputation is to make sure that your mailing list meets our opt-in requirements. Lists that meet these requirements always return better open rates, better click-throughs, and far fewer complaints and unsubscribes.
Lists that do not meet these requirements usually result in damaged email reputations and can result in account suspension.
From time to time, it's a good idea to revisit your mailing list and trim out subscribers that have not opened an email in a long time. Some email providers (e.g. Gmail) may begin to penalize a sender's reputation if they continue to send to recipients that no longer open their emails. You can learn more about retiring unengaged subscribers in this help article.
Custom Tracking Domain Name
This last step is recommended for users of Direct Mail that send using their own SMTP server. In order to more fully isolate your reputation from other users of Direct Mail, you may want to set up your own custom tracking domain name. This means that when users click on a link on your message, they'll see your domain name instead of a domain name that belongs to Direct Mail. If you already have your own domain name (for business or personal reasons), then adding a custom tracking domain name is almost always free and easy to set up. How to set up a custom tracking domain name.
If you are sending via e3 Delivery Service, we manage this step for you via custom subdomains. If you like, however, you can still set up your own custom tracking domain for added protection.