Suppression Lists – What are they?
An email suppression list is a list of contacts that you do not want to send to because sending to these contacts could hurt your sending reputation and delivery rates. Basic categories for suppression lists include spam complaints, bounced & blocked mail, and unsubscribes.
Spam Complaints
Sending an email to someone after they have submitted your email as SPAM can be very harmful to your sending reputation. If this practice is repeated, your IP and/ or domain may soon be blocked by the ISP (Internet Service Provider).
Always follow best practices and protocols, especially when handling spam complaints.
Bounced & Blocked
Keeping up with bounce details is an essential practice. If you are receiving “Invalid Address” bounces, you should be moving these contacts to the suppression list right away. These are usually typos or old addresses that have timed out and been turned off by ESPs (Email Service Providers). These contacts are classic picks for spam traps, which will hurt your reputation if you continue to attempt contact.
If you are seeing “Blocked” bounces, this indicates that the recipient does not desire to have your campaign. Unless you have received explicit permission from a contact with this bounce, pass them to your suppression list. If your mail has been requested, try to reach out to the person directly. You may be experiencing this block due to an automatic filter that needs to be updated to allow your mailings. Until you have confirmed that this has been completed, do not send any mail to this contact.
If you are receiving a hard bounce, the general rule of thumb action is to move them to your suppression list.
Unsubscribes
As per the CAN-SPAM Act of 2003 (The Controlling the Assault of Non-Solicited Pornography And Marketing Act of 2003 is a law passed in 2003 establishing the United States’ first national standards for the sending of commercial e-mail), you should give your recipients an option to opt out of email campaigns. When someone unsubscribes, they should be added to an email suppression list to help you prevent sending emails to them in the future. This should be done immediately.
Make it easy to find your unsubscribe options. When a recipient is unable to find this information quickly, it’s more likely they will mark your mail as SPAM. Unsubscribes do not hurt your sending reputation. However, being flagged as SPAM does!
Suppression lists allow you to stop sending to recipients who do not want your campaigns. Keeping these contacts on your active lists will only hurt your overall reputation. Preference centers give your recipients more options to adjust the content that they want to see. It would also allow them to unsubscribe from your campaigns completely. As you know, good engagement is imperative for any marketing campaign. Keeping regular list hygiene practices helps to keep open and click rates high, negative flags from ISPs low, and ultimately helps to keep a good sending reputation across the board.