How often should I clean my email list?

The answer depends on how much mail you're sending. But the real answer is: whenever your list shows signs of decay.

Here's the breakdown by sending volume. High-volume senders (sending daily or multiple times a week) should clean monthly. You're acquiring new addresses constantly, and you're hitting bounces frequently. You need that monthly refresh to catch bad addresses before they hurt your reputation. Medium-volume senders (a few times a month) can clean quarterly. Low-volume senders (once a month or less) can stretch to every six to twelve months.

But here's the thing. If your list has been sitting inactive for more than six months, you need to clean it before your next send, regardless of your normal schedule. Email list decay is real. B2B lists decay about 20-25% per year because people change jobs and companies close. B2C lists decay more slowly, but they still decay. If your list sat untouched for half a year, a significant chunk of it is probably dead or broken.

The timing here makes sense because it aligns with natural list decay. You're cleaning out the damage that's happened since the last clean, not preventing it.

Don't just set a calendar reminder and forget about it. Watch your bounce rates and engagement rates. If bounces suddenly spike or engagement tanks, clean your list immediately. Sometimes decay hits faster than expected.