Migrate Emails Between 1&1 IONOS Email Accounts

For Mail Basic and Mail Business Accounts

Learn how to migrate the email messages from your old 1&1 IONOS Mail Basic or 1&1 IONOS Mail Business accounts to your recreated accounts after you've completed an internal domain transfer.

Your email accounts do not move with your domain when you move the domain from a package, such as with an internal domain transfer between packages. Instead, the email accounts associated with the transferred domain are renamed with a new domain since the domain they were originally created with is no longer available. This helps to ensure that your messages are not accidentally deleted by moving the domain.

The email accounts will be renamed with the ending _0@mailboxbackup.info and the original @ symbol will be changed to an underscore (_). For example, an email address originally named account@example.com will be renamed to account_example.com_0@mailboxbackup.info.

Please Note:

There is a 25-character limit for the renamed backup mailbox. For example, jonathansmith@verylongexampledomainname.com would be renamed as jonathansmith_verylongexa_0@mailboxbackup.info since "jonathansmith_verylongexa" is the maximum 25 characters.

You will need to recreate the original email address (in our example, account@example.com) in the package that the domain was transferred to and then import the emails from the _0@mailboxbackup.info address (in our example, account_example.com_0@mailboxbackup.info) to the recreated email address in the Webmail interface using the steps below.

Guided Steps

  • Log in to 1&1 IONOS Webmail.
  • Click the Add Mail Account link in the menu on the left below your folders (Inbox, Drafts, Sent Objects, etc.).
  • Enter the _0@mailboxbackup.info address you are migrating and the password for that account (This is the same password used for the account prior to the domain transfer). Then, click Add.
  • A Warning message will be displayed. Click Ignore Warnings.
  • If the Auto-configuration fails, click the Manual button.
  • In the Account Settings section, enter an Account name (used to describe the account), Your name, and the _0@mailboxbackup.info address you are migrating if it is not already there.
  • Scroll down to the Incoming Server section and choose/enter the following information:
Field Entry
Server Type IMAP
Server Name imap.ionos.com
Connection Security SSL/TLS
Server Port 993
Username The _0@mailboxbackup.info address entered in Step 4
Password The password previously used for the mailbox
  • Scroll down to the Outgoing server (SMTP) section, and choose/enter the following information:
Field Entry
Server Name smtp.ionos.com
Connection Security StartTLS
Server Port 587
Authentication As incoming mail server
  • Click Save.
  • Click the arrow to the left of the newly-added account to expand the view of its folders.
  • In the list of folders for the newly-added account, right-click on the Inbox (or other folder containing messages you would like to migrate) and select Move all messages.
  • Select the folder into which you are moving the messages, and click Move all. If you are moving the Inbox, for example, the Inbox you are moving messages into should already be highlighted by default.

Please Note

Moving folders that contain a large number of messages may take an extended period of time to complete. This process will run in the background until all of the messages have been moved.

Your new email account will now contain all of the messages you migrated. If you find that any messages were missed during this migration, you will still be able to access them and repeat this process as long as you do not deleted the _0@mailboxbackup.info mailbox or cancel the package it is contained in.