Parallels Plesk Atmail and Error: Password file could not be found

When logging into the Atmail webmail interface used by Parallels Plesk, you might receive the following error: Error: Password file could not be found If you take a look in the log files for the Atmail vhost (/var/log/atmail/error_log) then you should see something along the lines of: PHP Warning: file_exists() [function.file-exists]: open_basedir restriction in effect. File(/etc/psa-webmail/atmail/.atmail.shadow) is not within the...