Enabling the "Do not deliver copies of forwarded emails to the Plesk mailbox" mail Forwarding option on mailbox in Plesk does not have any effect

Symptoms

• Plesk Obsidian running on a Linux-based operating system

• When Forwarding is enabled for a Plesk mailbox via Plesk > Domains > example.com > Mail > Mail Accounts > example@example.com > Forwarding tab, enabling the option Do not deliver copies of forwarded emails to the Plesk mailbox on mailbox in Plesk (on Forwarding tab) does not work.
  

• It is required to run plesk repair mail each time this option is enabled or disabled in order for it to become effective

Cause

During a Plesk update to 18.0.59, the .qmail files in affected mailboxes were not updated correctly (most likely due to an update interruption).

Resolution

1. Connect to the server via SSH

2. Correct the .qmail files in affected mailboxes by executing the following command:

   # find /var/qmail/mailnames -mindepth 3 -maxdepth 3 -type f -name .qmail -execdir sed -i 's/ORIGINAL_RECIPIENT:-DELIVERED_TO/ORIGINAL_RECIPIENT:-\$DELIVERED_TO/' {} \;

3. Run plesk repair mail -y

Additional information

Plesk Repair Utility: Mail | Plesk Obsidian documentation