There is also an option to allow open relay without authorization, which, by default, is hidden from the user interface. Opening mail relay without authorization is not recommended because it allows spammers to send unsolicited mail through your server. If you want to set the open relay, log in to the server's file system, locate the file root.controls.lock in your Parallels Plesk Panel installation directory (PRODUCT_ROOT_D/var/root.controls.lock on Unix and PRODUCT_DATA_D/var/root.controls.lock on Windows platforms) and remove the line /server/mail.php3:relay_open from this file. The open relay option will show in your control panel.
# Select the webmail program that should be available to the users.
# Select the antivirus program that should be used on the server.
# Select the spam protection option that should be used on the server.
# Select the mail account name format.
Selecting the Use of short and full names is allowed option will allow users to log in to their mail accounts by specifying only the left part of e-mail address before the @ sign (for example, username), or by specifying the full e-mail address (for example,
[email protected]).
To avoid possible authorization problems for e-mail users who reside in different domains but have identical user names and passwords, we recommend that you choose the Only use of full mail account names is allowed option.
Once you have set your mail server to support only full mail account names, you will not be able to switch back to supporting short account names until you make sure there are no encrypted passwords for mailboxes and user accounts with coinciding user names and passwords residing in different domains.