Unable to send mail using the horde webmail

The error message will look like this:

Check the log message of horde (psa-horde.log). This will be dependant according to the horde set
ting. Here it is /var/log/psa-horde/psa-horde.log :
HORDE [error] [imp] Failed to connect to localhost:25 [SMTP: Failed to connect socket: (code: -1
, response: )] [on line 1070 of "/usr/share/psa-horde/imp/compose.php"]

Check whether the "telnet localhost 25" is connecting in server.

If not then do the following:
cd /etc/xinetd.d/
ln -s smtp_psa smtp
/etc/init.d/xinetd restart

It is doesn't fix, then check the /etc/hosts. Check whether "localhost" is preset in it:
#127.0.0.1 www.NAME www
127.0.0.1 localhost www.NAME