EMAIL MIGRATION
CHECKER
Moving email between hosts goes wrong in a handful of predictable ways, and all of them are visible in DNS before you start. This runs the five checks that matter: where mail currently goes, the MX record TTL that decides how long mail keeps landing on the old server after you switch, and whether SPF, DKIM and DMARC are in a state that will survive the cutover.
What is an Email Migration Checker?
An email migration checker is a free tool that tells you whether a domain is ready to move email providers. It reads the current MX records and the TTL that determines how long mail keeps reaching the old server after a change, then checks SPF, DKIM and DMARC for the specific problems that break a migration, such as SPF already near its ten-lookup limit.
How does an Email Migration Checker work?
- 01We read the current MX records and identify the provider behind them.
- 02The MX TTL is read live, because it sets how long the old server keeps receiving mail after a change.
- 03SPF, DKIM and DMARC are each checked for the specific failures that break a migration.
Frequently asked questions
How long before a migration should I lower the TTL?
At least 24 hours, and ideally as long as the current TTL itself. Lowering the TTL only takes effect once the old, longer value has expired from every resolver that cached it, so dropping a 24-hour TTL to 300 seconds an hour before the cutover achieves nothing. Lower it a day ahead, migrate, then raise it again once mail is flowing correctly.
Will I lose email during the migration?
You should not, if the old mailboxes stay active. Sending servers that still have the old MX cached deliver there, and well-behaved ones retry for several days if a server rejects mail. The real risk is decommissioning the old host too early: keep it accepting mail for at least a week after the switch, and only then shut it down.
What breaks SPF during an email migration?
The ten DNS lookup limit. You need both the old and new providers listed while mail can come from either, and each include mechanism costs one to three lookups. Domains already sitting at seven or eight tip over the limit the moment the second provider is added, at which point SPF returns permerror and is treated as absent. Check the count before you start, not after.