Migration fails with an error: Login failed. Server answer ABCD_2 NO LOGIN bad username or password

Symptoms

Migration fails with the following error:

PLESK_ERROR: Error when backing up mail messages of mailbox 'jdoe@example.com' on the source server. Command: C:\plesk_migrator\MailMigrator.exe backup --account-description-file=C:\plesk_migrator\mail\example.com\jdoe\mailbox-description --exclude-message-ids-file=C:\plesk_migrator\mail\example.com\jdoe\exclude-message-ids Exit code: 2 Stderr: Error: Cannot conect to mail server localhost:143. Authentication for mailbox jdoe@example.com failed. Reason: Login failed. Server answer ABCD_2 NO LOGIN bad username or password

Cause

The jdoe@example.com mailbox's password stored in Plesk does not match the password stored in SmarterMail.

Resolution

Update the password for jdoe@example.com via Plesk GUI:

1. Log in to Plesk on the source server
2. Navigate to Domains > example.com > Mail Accounts
3. Set a new password for jdoe@example.com
4. Log in to Plesk on the target server
5. Press Reload Source Data in Tools & Settings > Migration and Transfer Manager > 203.0.113.2
6. Re-sync business objects and mail data for the example.com subscription.