Should suppressions be global or list-specific?

The simple answer is: it depends on your sending structure. But here's where a lot of senders get it wrong.

If you've got one brand or one domain sending all your email, then yes, suppressions should be global. When someone unsubscribes or a hard bounce hits, they're telling you they don't want email from you at all. Period. A global suppression respects that decision across every list and segment you manage.

But here's the thing: not everyone operates that way. If you're a multi-brand company with separate consent records for each brand, or if you're running transactional and marketing from different domains, list-specific suppressions can make sense. Someone might want your purchase receipts but not your marketing newsletter. They're different consent agreements. You shouldn't suppress them globally.

The risk with list-specific suppressions is accidental re-mail. You suppress an address in List A but forget it's also in List B. That person gets mailed anyway. Global suppressions prevent that mess.

Here's the decision tree: Do you own multiple brands with separate opt-in records? Are you sending transactional and marketing from different domains? If yes, list-specific suppressions fit. If no, go global. And either way, your ESP should be removing suppressions automatically before every send.

Next step: Check your GDPR compliance and suppression strategy, and audit your current list to find suppressions you might have missed.