- Plesk for Linux
IMAP connection works, but it starts with connecting to IPv6:
# telnet localhost 143
telnet: connect to address ::1: Connection timed out
Connected to localhost.
Escape character is '^]'.
When accessing webmail, the following error message appears:
PLESK_INFO: Error connecting to mail server
If Horde is used: The following error message appears in the logfile /var/log/psa-horde/psa-horde.log:
CONFIG_TEXT: ERR: HORDE [horde] FAILED LOGIN for email@example.com (firstname.lastname@example.org) [203.0.113.2] to Horde [pid 525926 on line 211 of "/usr/share/psa-horde/login.php"]
If Roundcube is used: The following error message appears in the logfile /var/log/httpd/error_log:
CONFIG_TEXT: mod_fcgid: read data timeout in 45 seconds, referer: http://webmail.example.com/
Premature end of script headers: index.php, referer: http://webmail.example.com/
Localhost is using IPv6 and the "ip6tables" utility blocks connection to mail ports.
Open mail ports 25, 587, 110, 143, 993 for IPv6 using ip6tables.