Unable to re-sync mail content of subscription: Failed to copy mail content of subscription. Most probably that happens because of a network-related issue

Symptoms

• Failed to re-sync mail messages of a migrated subscription via Plesk Migrator

• The following error is shown in the migration report at Tools & Settings > Migration and Transfer Manager > 203.0.113.2 > example.com [Details]:

  Failed to copy mail content of subscription. Most probably that happens because of a network-related issue. Check network connections between source and target servers, then run migration for that subscription once more.
  Migration tools tried to perform operation in 3 attempts: Failed to execute remote command on '203.0.113.2' server. Check debug log (usually at "%SYSTEMDRIVE%plesk_migratorrpc-agentdebug.log") for more details.

• In C:plesk_migratorrpc-agentdebug.log on the source server below error can be found:

  IOError: [Errno 13] Permission denied: 'C:plesk_migratorMailMigrator.exe'

• On the source server there is a process MailMigrator.exe in Task Manager

Cause

The MailMigrator.exe process stuck.

Resolution

1. Connect to the source server via RDP
2. Open the Task Manager
3. Kill the MailMigrator.exe process
4. Re-sync mail messages for subscription once again