Operating System was Linux
No one was able to login to Plesk’s default webmail, horde. Enabled error reporting in php.ini and got the error message as below in the “/etc/httpd/logs/error_log” and/or “/var/log/psa-horde/psa-horde.log”
PHP Warning: Unknown(): Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/usr/local/psa/admin/sessions) in Unknown on line 0, referer: http://webmail.supportsages.com/test.php?mode=unregister
Here the solution was to edit the php.ini to use /tmp as the session.save_path or even “/var/lib/php/session”
Other solution, for similar issue (not this exact error though) is to set,
session.auto_start = 0 in php.ini
Making sure that localhost entry is in /etc/hosts and resolves. For that do a telnet localhost 143 and if you get “Connected to” message, its not that issue
check /etc/hosts file. It must have permissions -rw-r–r– (644) on a ls -l
Whatever be the session.save_path setting in the php.ini, it should have the permission of 1777
Run IMP test to check the problem at: http://webmail.DOMAIN.COM/horde/imp/test.php and make sure that you get the green words for all the tests.
This problem may occur if the domain’s web content is hosted on another server and the MX DNS record doesn’t exist or points not to the Plesk server. IMP tries to check mail on whatever server the domain name resolves to. In order to prevent this from happening the domain name or MX record (if it exists) must be resolved locally to the server.
References : http://kb.parallels.com/article_41_260_en.html
Related posts:
How can you access hoard if you’re mx records are supposed to point to another server?
You should access the emails at the mail server where MX record is pointed to. If it is a pointed to a Plesk enabled mail server, you can access it by http://ip.ip.ip.ip:8425, or else you can configure the horde to use that mail server, if all the accounts in the server is using another mail server.