[horde] Mailer SMTP option not working

[Jeff Tipton]

 >Zitat von Vilius ?umskas <vilius at lnk.lt>:

 >> Sveiki,
 >>
 >> Monday, September 26, 2011, 12:00:28 PM, you wrote:
 >>
 >> >>> $conf['mailer']['params']['host'] = 'hostname.domainname.local';
 >> >>> $conf['mailer']['params']['port'] = 25;
 >> >>> $conf['mailer']['params']['auth'] = 'PLAIN';
 >> >>> $conf['mailer']['type'] = 'smtp';
 >>
 >> Not sure how mailer part works in Horde but you have PLAIN set for
 >> authentication, but no username and password.
 >
 >In that case Horde is using the user's login credentials. But the logs
 >didn't say anything about failed authentication. The question rather
 >is if PLAIN authentication is supported at all (by the server).
 >
 >Jan.
 >

Yes, PLAIN is enabled:

www# telnet hostname.domainname.local 25
Trying 192.168.2.11...
Connected to hostname.domainname.local.
Escape character is '^]'.
220 mail.domainname.tld ESMTP
ehlo domainname.tld
250-mail.domainname.tld
250-PIPELINING
250-SIZE 32768000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
quit
221 2.0.0 Bye
Connection closed by foreign host.
www#

One, perhaps, interesting thing. I tried to echo some variables from 
Horde's php shell, and I could get values from:

horde/config/conf.php,
horde/turba/config/conf.php,
horde/turba/config/backends.local.php
horde/imp/config/conf.php

But I got no variable values from horde/imp/config/backends.local.php, 
where I set 'smtphost' 'smtpport'.

Jeff