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Why Email Suppression List Management is Important

There’s nothing quite like that feeling of receiving an email from a company you swear you already unsubscribed from.

Companies are required to honor unsubscribe requests within 10 business days, but improper email suppression list management and subdomain sending best practices can cause these requests to fall through the cracks.

Email providers, however, don’t care if it’s accidental when it comes to your sending reputation. Here’s how to avoid staying out of the penalty box.

Non-Matching Suppression Lists

Sending from several email providers is fairly common in our industry, especially for large volume senders. The big reason is that one provider acts as a backup in case issues arise. But performance and financial considerations with monthly volumes are other examples of why a multi-provider approach is normal.

There’s also snowshoeing, which is a term used for spammers that use a plethora of providers to spread their filth in order to fly under the radar. For our purposes, we’ll focus on non-malicious email senders in this post.

One element of using different providers is that each has its own email suppression list made up of hard bounces, complaints, and unsubscribes. Smart companies will run their operations off a single database that takes in all that data and flags it accordingly, ensuring that an unsubscribe through provider A won’t get an email from provider B.

We have worked with senders where we found that isn’t the case and those lists don’t match up, however. That leads to increased complaints and a lower sending reputation, which isn’t good for anyone.

The easiest and best fix: Use a unified database. Otherwise, you’ll have to manually add unsubscribe requests to your email suppression list every day, which doesn’t sound like a lot of fun.

Forgetting To Pack Up The Suppressions When You Move

Anyone that has tried to fit a couch through a doorway can agree that moving is really the worst. Moving email providers is usually a much easier and less strenuous process.

But just like you forgot to clean out your bathroom closet, senders can often forget to bring their suppression lists with them when moving to a new provider. If they are not using that unified database, you can see where troubles might arise.

If you move to a new provider, make sure you are uploading your email suppression list to your new home before you send to ensure you don’t accidentally send to everyone who unsubscribed from you.

Sending Similar Content from Subdomains

Another set of problems can arise when email marketers utilize top-level domains ( and subdomains ( to send the same content. If a user unsubscribes from the top-level domain but still gets content from the subdomain, there’s something broken in that system that needs to be addressed. This is fairly rare, but is something to look into if you’re getting complaints from users.

For senders, all of the above should be easy to maintain and a simple checkbox when it comes to data cleanliness. For getting email to the inbox and keeping a great sending reputation, the risks of not keeping up with email suppression list management can be destructive at best.

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Whois: Josh Nason

Josh Nason is a Reputation Manager at Oracle Dyn Global Business Unit, a pioneer in managed DNS and a leader in cloud-based infrastructure that connects users with digital content and experiences across a global internet.