Back up important mail and confirm the new address is available on the same domain. Review aliases, forwarding, mailing lists and applications using the old address. Decide whether the old address should remain as an alias during a transition.

1. Open Mail in Plesk and select the mailbox to rename.
2. Edit the address field available in the mailbox settings and enter the new local part. Confirm the domain and review any warnings concerning linked users or account identity.
3. Save the change. Reopen the mailbox entry to confirm the new full address and review the retained mailbox settings.
4. Update mail-client usernames, outgoing From addresses, website SMTP credentials, signatures and account-recovery references that used the old address.
5. If appropriate and available, add the old address as an alias of the renamed mailbox. Check for conflicts before doing so, and document when the alias should be reviewed.

Sign in with the new full address and confirm existing folders and messages. Send and receive externally using the new address. If an old-address alias was configured, test that address independently as well.

If renaming is unavailable for your mail server or role, use a planned new-mailbox migration rather than deleting the original. If a client fails after the change, check its stored username and sender settings. For an address change across different domains or providers, treat it as a migration with separate data and routing steps, not a simple rename.

• Creating an email mailbox in Plesk
• Opening Plesk webmail securely
• Changing a mailbox password in Plesk

• Plesk: Managing Mail Accounts
• Plesk: Mail Account Settings