Cleaning a list before it reaches ConvertKit

Subscribers carry tags rather than list membership, so an export is one flat file with tag columns. Creators frequently have several lead magnets feeding the same pool, and the tag is the only clue about which one produced a given address.

Subscribers, apply a filter or tag, then Export. ConvertKit emails a CSV.

Before importing from another platform, and after any lead magnet campaign. Free downloads attract throwaway addresses at a rate no other acquisition source matches.

Some addresses come back unresolved, and that is a fact about the receiving server rather than a gap in the check. We label those and never bill for them. What that means, and why roughly 28% of business addresses land there, is set out on our page about catch-all domains.

Say you're an author with 18,500 subscribers and you run a paid social campaign for a free editing checklist. Six thousand people sign up in a week. The platform, which now calls itself Kit, bills on confirmed subscribers, so your count is suddenly 24,500 and the plan moves up to match.

Run the new signups through a check and suppose 780 are invalid and 410 sit on disposable domains. That's 1,190 people who got the PDF and will never open an email. Kit's help center says bounced, unsubscribed and unconfirmed subscribers don't count toward billing, so the 780 would fall out after your first broadcast bounces. The 410 disposables are different. They accept mail, never bounce, and stay on your bill until you remove them. Tag both groups before the welcome sequence starts, and a 10,000 pack at $25 covers the whole campaign with credits left for the next one.

Kit labels a subscriber cold when they haven't opened or clicked in 90 days and have been on your list at least 30. Cold subscribers are still confirmed, and the help center is clear that they count toward your bill. A verification pass won't find them, because the mailbox exists and answers. All we can tell you is that an address can receive mail, and whether anyone reads it is something only your own open data shows.

So you need two passes. Verify to remove what can't be delivered, then use Kit's cold filter to send a short re-engagement email and prune whoever stays silent.

One import detail is worth checking in your own account. If your forms use double opt-in, confirm whether a CSV import sends a confirmation email or treats everyone as confirmed straight away, because the second case makes them billable the moment the upload finishes.