How often should blocklist checks be run?

You've just sent a big campaign and everything looks fine. But somewhere out there, a blocklist has quietly flagged your IP or domain. Your emails are bouncing or silently failing, and you won't know it until someone complains or your stats fall off a cliff. That's the cost of checking too rarely.

So how often should you actually check? It depends on how much you're sending.

Low-volume senders (fewer than 50,000 emails a month) can get away with weekly checks. You're not in the danger zone very often, and problems tend to surface more slowly. That said, always run a manual check before a major campaign launch, just to start clean.

Mid-volume senders (50,000 to 500,000 a month) should be running daily checks. A listing that sits unnoticed for even 24 hours can quietly corrupt your delivery rates and sender reputation. Daily keeps you in the loop without becoming a full-time job.

High-volume senders (500,000 or more a month) really need continuous monitoring, think hourly or better. When you're sending at that scale, a few hours of blocked delivery can mean tens of thousands of failed sends. That's not a rounding error, that's a real problem.

The honest shortcut is to use a blocklist monitoring service. These tools check continuously and alert you the moment something appears. You don't have to remember to check. You just get a ping when something goes wrong.

Also run an immediate check after any infrastructure change (new IP, new sending domain, new ESP), not just on a schedule. Those moments are when listings happen.

The cost of monitoring is basically nothing compared to the cost of a listing that compounds over days. Don't let it get there.

You can run a quick check right now with our free Blocklist Checker. Takes about 30 seconds.