Switching email providers is the migration of a mailbox from one provider to another, covering old mail, contacts and calendar data. There is no fully automated way to merge Google accounts into one account, so the transfer happens app by app. Mail stays reachable through an overlap month: both accounts stay open, old mail is copied to the new account, new mail is forwarded from the old account to the new account, and the old account closes only once nothing of value still arrives there.
The overlap month
During the overlap month, the old account and the new account both operate, because no import tool moves every part of a mailbox in a single pass. The new account becomes the daily mailbox from the start, while the old account stays open as a safety net for mail that still goes to the old address. Gmail automatic forwarding sends a verification link to the destination address before forwarding starts, passes on all new messages except spam, and gives the account holder the choice of keeping, archiving or deleting the copy in the old inbox. The overlap ends when the old inbox receives nothing except mail that is already expected to go elsewhere, and the forwarding rule is then removed rather than left running without review.
Old mail and folders
Old mail moves through one of three routes: a provider import tool, a mailbox export file, or a desktop mail client that holds both accounts. Each route moves messages but not the full mailbox structure, so the choice depends on whether folders, labels or a complete archive matter most.
| Route | What it moves | Limit |
|---|---|---|
| Provider import tool | Messages into the new account | Folders and labels do not transfer |
| Mailbox export file | The whole mailbox as an archive file | A mail client is needed to import it |
| Desktop mail client | Messages between accounts over IMAP | Folder copying is manual |
Gmail import brings messages from another account into Gmail without their folders or labels, so a folder structure from the old provider arrives flattened into Gmail labels or into a single set of imported messages depending on the import path. After a Gmail import, Gmail forwards messages sent to the other account for 30 days, and the new Gmail address stays visible as a reminder for 60 days or until the reminder is deleted. Those two windows are why a month of overlap fits the Gmail case. They are Gmail behaviour rather than a general rule, since other providers set different windows or none at all.
A mailbox export is the second route. Google Takeout builds the mailbox archive in MBOX format, with the mail sitting in the Takeout folder as one or more .mbox files that a desktop mail client imports, and the export itself takes minutes to days depending on mailbox size, according to an InboxPilot guide to exporting Gmail. Apple Mail imports messages exported in mbox format and places them in a new mailbox called Import in the Mail sidebar, from which folders and messages can be dragged into other mailboxes. The Apple Mail import flow on a Mac follows File, then Import Mailboxes, with the imported messages landing in an Import mailbox under On My Mac before being reorganised.
A desktop mail client is the third route. A third-party guide describes Thunderbird as able to hold both the old account and the new account at once, so messages can be copied from folders in one account into folders in the other account over IMAP. For a move from Outlook into Google Workspace, Google recommends Google Workspace Migration for Microsoft Outlook for mail, contacts and calendar events, which is a dedicated migration tool rather than the consumer import path. Outlook.com once offered an import wizard for Yahoo Mail and many IMAP providers, but that description dates from 2014, and Microsoft has since removed the ability to connect new third-party accounts inside Outlook.com and to sync existing connected accounts there, so the 2014 description cannot be treated as the current position.
Contacts and calendars
Contact transfer is a file export followed by a file import, not a live sync between providers, and the files are usually in CSV or vCard format. Microsoft documents a transfer between Outlook and Google Gmail in both directions, with Google Contacts exported in Outlook CSV format and imported through the Outlook import wizard, and the same file route works in reverse from Outlook contacts into Google Contacts. Contact pictures are not exported in the Gmail contacts export, so photos attached to contacts are lost in the file transfer even when names, addresses and phone numbers survive.
Calendar data moves separately from contacts, through an ICS file export from the old calendar and an ICS import into the new calendar. Google Calendar accepts ICS files for import and states that guests and conference data for an imported event are not imported, so shared calendars need checking after import. The contact and calendar steps belong before the cutover, because a new account that sends mail without the old address book forces the account holder to rebuild contacts from memory when they are most needed.
Forwarding and the cutover
Providers handle forwarding differently, and the differences matter during the overlap. Outlook rules draw a distinction between forwarding and redirecting: a forwarded message appears to come from the forwarder, so replies go to the forwarder, while a redirected message appears to come from the original sender, so replies go to the original sender. That distinction decides which rule fits the overlap, since forwarding keeps replies routed through the old account while redirecting preserves the original sender for replies.
iCloud Mail forwarding applies both to mail sent to the iCloud address itself and to mail sent to custom domain addresses set up for iCloud Mail, and it offers a delete-after-forwarding option, with stored forwarded copies consuming iCloud storage space. iCloud.com rules add a forward-to action for selected messages, allow up to 500 rules, and take up to 15 minutes for new and edited rules to come into effect, without affecting existing mail.
Forwarding moves only new mail, never old mail. Old mail needs its own step: an import tool, a mailbox export, or copying messages through a desktop mail client.
The cutover itself is a sequence rather than a single action: forwarding is verified by sending test mail to the old address and confirming arrival in the new inbox, the old inbox is checked for anything still arriving that matters, sending from the new address is confirmed, and only then is forwarding removed and the old account closed or left dormant.
Sending from the old address
During a switch, sending identity lags behind receiving, since contacts and services keep replying to the address they already know. Send-as addresses let mail still go out from the old address while the new account is the main mailbox, and the old address stays usable for sending until the point where replies to it stop mattering, since removing it breaks conversations that started before the switch. Services that send security codes and password resets to the old address are the main reason to keep sending from the old address available during the overlap, because a reset flow that points at a closed address cannot complete. The sending step is also where the distinction between migrating a provider and changing an address on each service becomes visible: migrating the provider changes where mail lives, while changing the address on each service changes where each service sends mail, and the two jobs overlap but are not the same job.
Account closure and recovery
Account closure comes last, and it leaves the least room for correction, because deletion removes the safety net the overlap month provided. The account holder confirms three things before closure: the new inbox holds the old mail that matters, contacts and calendar data are present in the new account, and no service still depends on the old address for sign-in or recovery. Recovery of a deleted account is time-limited and is not guaranteed, and no single recovery window is stated here because primary provider documentation found during research does not state one figure and secondary sources disagree.
A dormant account still receives mail that can be checked, while a deleted account cannot receive anything at all. Dormant accounts carry their own cost, because an unmonitored inbox can accumulate password resets and security alerts that nobody reads, so dormancy works as a short bridge rather than a permanent arrangement.
Alias addresses and provider independence
An alias changes what the next provider switch costs, because the address held by a service is an alias forwarding to a destination inbox, and the destination can change while the alias stays the same. When a mailbox owner switches providers, the alias destination changes from the old inbox to the new inbox, and mail sent to the alias follows the new destination, while the alias itself stays the same.
AliasFleet provides forwarding aliases of this kind. Its free plan includes 10 active forwarding privacy aliases and 1 verified destination inbox, and paid plans add further aliases and destination inboxes. AliasFleet does not store the mailbox itself: it forwards mail to a destination inbox owned by the account holder, so switching providers still requires migrating the old provider mailbox, and the alias layer does not move old mail, contacts or calendar data on its own. AliasFleet also does not remove the need for an overlap month on the first switch into an alias setup, because services that already hold a direct provider address keep sending to that address until the address on each service changes. The benefit appears on the second switch and every switch after it, when the destination change is a single setting rather than an address change at every service.
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