Thirty minutes a month beats a rescue project a year
Nothing is broken. That's precisely why this is the moment to put a routine in place, because every emergency cleaning project in this field started with a list nobody was watching.
The routine is deliberately short. A monthly task that takes half a day gets skipped by March, and a skipped routine is the same as not having one.
The order the work happens in
Read three numbers from last month's sends
Hard bounce rate, complaint rate, and the share of the list that opened anything. Write them somewhere that keeps history, because the trend is the signal rather than the value.
Act on anything the platform suppressed
Confirm hard bounces were suppressed on first failure and that complaints were removed everywhere, including the ad audiences your platform syncs to.
Apply the sunset rule
Move anybody past your inactivity threshold out of the campaign list. This is the step that does the most and costs nothing.
Verify only what needs it
The segment about to receive something it has not received recently. Most months that is a small slice, and in some months it is nothing at all.
Look at where new addresses came from
One bad source produces most bad addresses. A month of signups grouped by form or campaign shows you which one to fix.
What each result means here
The same four results and their flags, read against this job. A catch-all worth keeping in one situation is one to exclude in another.
| Result | What to do with it |
|---|---|
| Valid | Nothing to do. Stamp the date so next month's check knows what is already fresh. |
| Invalid | Suppress and note which source it came from, because that is the number that changes anything. |
| Catch-all | Leave tagged and keep mailing while engagement holds. Review yearly rather than monthly. |
| Unknown | Re-check next month. A monthly rhythm is exactly the cadence that resolves these eventually. |
| Role flag | Nothing monthly. Review the segment's complaint rate quarterly instead. |
| Disposable flag | Remove, and add the domain to the block list at your signup form. |
How you know it is finished
The three numbers are recorded with a date, the suppressions and the sunset rule have run, and the whole thing took under an hour. If it took longer, the routine's too big and you'll abandon it.
What this does not fix
Most months this fits inside the 100 free credits, because the segment needing a check is small. Credits never expire, so a quiet month does not cost you anything bought in a busy one.
Questions people ask
Is monthly the right frequency?
For most senders, yes, because it's short enough that a problem is still small when you see it. If you send daily at volume, look at the same numbers weekly. If you send twice a year, check before each send instead.
Do I need to verify the whole list every month?
No, and doing so wastes your money on addresses you checked recently and have not mailed since. Verify the segment about to receive something after a gap.
Which number matters most?
Your complaint rate. It damages a sending reputation faster than bounces do, and it comes from people whose mailboxes work perfectly, so no amount of cleaning will touch it.
Try it on the file in front of you
100 free checks a month, no card. Addresses we could not get an answer on come back labeled as unknown, and those are not billed.