How should unsubscribes and complaints interact?

Someone hits "unsubscribe" and someone else hits "report spam" on the same campaign. Both result in the same outcome on the surface: they stop receiving your emails. But behind the scenes, these two signals are very different, and if you treat them the same way, you're missing important information.

An unsubscribe is a controlled opt-out. It says "I don't want this anymore." That's normal, healthy list behavior. A complaint says "I didn't want this, or something felt wrong." That's a reputation signal, and mailbox providers like Gmail and Outlook are watching your complaint rate closely.

Both addresses must be suppressed immediately. That part's non-negotiable. But here's what many senders get wrong: they merge both into one undifferentiated suppression list and lose the reason entirely. You want to tag each record with its source.

A practical structure looks like this:

• Unsubscribes: suppress from all marketing sends, tag reason as "opt-out", keep the record in your suppression list permanently so they're never accidentally re-added from a new import or merged list
• Complaints: suppress immediately (ideally within hours of receiving the FBL signal), tag reason as "complaint", flag for investigation if the volume from a single campaign or segment spikes

The reason you tag them separately matters more than you might think. If someone complained once and later re-subscribes through a new signup form, you want to know that. You might still add them back, but you'll approach their re-engagement differently. If they complained twice, that's a different conversation entirely.

Complaints also carry a second job that unsubscribes don't: they're a diagnostic tool. A sudden spike in complaints from one campaign tells you something went wrong with content, targeting, or consent on that specific send. Unsubscribes tend to trickle in steadily. Complaints cluster. When they cluster, that's your cue to dig into what triggered them.

So some senders also apply a global suppression layer that covers both. This means that even if a contact appears on a freshly purchased list (which you shouldn't be using anyway) or is imported from a different source, they don't get mailed if they're already suppressed for any reason. It's a good safety net, and it's what global suppression is designed to do.

If you're not sure whether your current setup is actually suppressing both signals correctly across all your sending streams, our SOS hotline is free and we're happy to take a look with you.