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SELinux and .forward files

·144 words·1 min
If you want to forward e-mail from root to another user, you can usually place a .



Forcing qmail to process e-mail in the queue

·92 words·1 min
Normally, qmail will be able to process the mail queue without any interaction from the system administrator, however, if you want to force it to process everything that is in the queue right now, you can do so:

sendmail: savemail panic

·139 words·1 min
If you see a large mail queue and your system’s I/O is increasing, you may find messages like these in your syslog:

Removing news feeds in Horde

·95 words·1 min
If you’ve used newer versions of Horde with Plesk, you have probably noticed the news feed that runs down the left side of the screen.


Dovecot: mbox: Can’t create root IMAP folder

·187 words·1 min
In some situations with dovecot running on your server, you may receive a message from your e-mail client stating that the “connection was interrupted with your mail server” or the “login process failed”.

Slow Horde login process with Plesk

·305 words·2 mins
I’ve seen quite a few situations where the Horde login process can take upwards of 45 minutes to log a user into the webmail interface.

Adjusting postfix queue time / lifetime

·69 words·1 min
If you want to adjust how long postfix will hold a piece of undeliverable mail in its queue, just adjust bounce_queue_lifetime.

Testing SpamAssassin with GTUBE

·44 words·1 min
If you have SpamAssassin installed, but you want to make sure that it is marking or filtering your e-mails, simply send an e-mail which contains the special line provided here:

Use a different IP for sending mail

·100 words·1 min
If you find yourself in a pinch and you need a temporary fix when your primary IP is blacklisted, use the following iptables rule:

Change Plesk back to short mail names

·145 words·1 min
If you have to use short e-mail usernames in Plesk (which is a bad idea), and someone accidentally sets the server to use full usernames, you can force Plesk to go back.

Enable SSL support in Postfix

·80 words·1 min
If you have postfix installed with OpenSSL support compiled in, you can enable SSL connections by editing two configuration files.

Adjusting qmail queue time / lifetime

·56 words·1 min
If you want to adjust how long e-mails will spend in the qmail queue before they’re bounced, simple set the queuelifetime:

Send Plesk e-mail to /dev/null or blackhole

·129 words·1 min
Should you find yourself needing to send e-mail destined for a certain account to a blackhole or to /dev/null, you’ll find very little information from Google.

Relay access denied

·151 words·1 min
If you’re checking through your mail logs, or you catch a bounced e-mail with “554 relay access denied” in the bounce, the issue can be related to a few different things:

Horde refreshes when logging in

·51 words·1 min
If you find that Horde (with Plesk) keeps refreshing when you attempt to log in, and there are no errors logged on the screen or in Apache’s logs, check the session.

Add SPF records to all domains in Plesk

·127 words·1 min
If you find yourself in the situation where you need to bulk add SPF records to every domain in Plesk, you can use this huge one-liner:

Telnet POP3 Commands

·36 words·1 min
If you ever need to communicate with a POP3 server via telnet to test it, here’s some commands you can use:

Setting the hostname in Sendmail

·33 words·1 min
If you need to change the hostname that Sendmail announces itself as, just add the following to sendmail.

Adjust max_execution_time for Horde in Plesk

·151 words·1 min
Often times, the wonderful webmail application known as Horde will spin out of control and cause unnecessary resource usage and often cause defunct Apache processes to appear.

Finding compromised mail accounts in Plesk

·291 words·2 mins
If odd bounced e-mails are coming back to the server or the server is listed in a blacklist, some accounts may be compromised on the server.

Verify that SSLv2 is disabled

·74 words·1 min
If you’re looking to get PCI/CISP compliance, or you just like better security, disable SSL version 2.

Repairing the qmail queue

·280 words·2 mins
There’s three main things to remember when it comes to the qmail queue:


Can’t Kill Sendmail Processes

·98 words·1 min
If you find yourself in the sticky situation where kill -9 still won’t kill a sendmail process, check the process list.

Fixing Invalid HELO’s

·329 words·2 mins
If your server is spewing an invalid HELO, you could be blacklisted pretty quickly.