Error: CentOS 5.6/Dovecot - Fatal: listen(::, 143) failed: Address already in use

You try to start Dovecot on CentOS 5.6 and get the following error:

Fatal: listen(::, 143) failed: Address already in use

Solution

Open /etc/dovecot.conf...

vi /etc/dovecot.conf

... and add the line listen = *:

[...]
#listen = *, [::]
listen = *
[...]

Then try to start Dovecot again:

/etc/init.d/dovecot start