How to enable short email names to log into postfix and webmail on a Linux Plesk server?

Question

I need to use short names to log into postfix and webmail (e.g., login with user instead of user@example.com), how can this be achieved on my Linux Plesk server?

Answer

Warning: Postfix does not support short mail names natively, because the internal logic for mailbox mapping and routing it has depends on the full email address. Forcing the ability to use short mail names can lead to issues such as the following:  

- Short usernames can collide (for example if you use info@example.com and info@example.org on the same server). 

- Users accidentally logging into the wrong mailbox, which can further lead to mailbox data leakage.  

- POP3/IMAP authentication can no longer distinguish accounts with the same local part across domains, because alias/virtual user mappings rely on full addresses  

Due to this, executing the steps below would be done solely at your own risk.
 

1. Connect to the server via SSH

2. Execute the following commands in order to force the usage of short mail names:

# plesk bin settings --set postfix-allow-short-mail-names=true

# plesk bin settings --set allow_short_pop3_names=enabled

# plesk sbin mailmng-server --set-accounts-format --account-format=both

3. Restart the Postfix service, in order to make the changes come into effect:

# systemctl restart postfix.service