Moving 15 years of email without a gap

dogrubakar.com lived on free Yandex mail for years, until it went read-only behind a paywall. The move to Google Workspace had one hard requirement: not a single lost email, not an hour of downtime.

Order matters more than tooling here. First the identity: create the mailbox on the new provider and confirm it accepts mail. Only then the MX cutover, because pointing MX at a server that does not know your address yet bounces real mail. Then SPF in the same breath, DKIM as soon as the provider allows it, and only after all of that, the old mailbox import over IMAP, which is a background job that can take days and does not care.

The part nobody tells you: the old provider will throttle your IMAP export to a few hundred messages an hour. Plan for the copy to take days, not minutes, and let it. New mail is already flowing to the new home; the archive can walk.