SMTP does not work over TLS

[Jochem Ippers]

Hi,
I've got no problems using imap over TLS, but I can only send mails 
using the
options not-encrypted + login, although postfix announces TLS + plain 
like it should.
Here's an excerpt from my postfix-log:

Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: TLS connection 
established from b006.ika.RWTH-Aachen.DE[134.130.21.6]: SSLv3
 with cipher RC4-MD5 (128/128 bits)
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: name_mask: noanonymous
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: connect from 
b006.ika.RWTH-Aachen.DE[134.130.21.6]
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 220 b009 ESMTP Postfix
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: watchdog_pat: 0x82382f0
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: < 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: EHLO b006.ika.rwth-aachen.de
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 250-b009
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 250-PIPELINING
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 250-SIZE 10240000
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 250-VRFY
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 250-ETRN
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 250-AUTH PLAIN LOGIN
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: match_hostname: 
b006.ika.RWTH-Aachen.DE ~? 127.0.0.0/8
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: match_hostaddr: 
134.130.21.6 ~? 127.0.0.0/8
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: match_hostname: 
b006.ika.RWTH-Aachen.DE ~? 134.130.20.0/23
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: match_hostaddr: 
134.130.21.6 ~? 134.130.20.0/23
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 250-XVERP
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 250 8BITMIME
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: watchdog_pat: 0x82382f0
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: < 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: QUIT
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: > 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: 221 Bye
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: disconnect from 
b006.ika.RWTH-Aachen.DE[134.130.21.6]
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: master_notify: status 1
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: connection closed
Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: watchdog_stop: 0x82382f0

Aug 10 11:29:46 b009 <info> postfix/smtpd[4419]: watchdog_start: 0x82382f0
Aug 10 11:30:02 b009 <info> postfix/smtpd[4418]: connect from 
b006.ika.RWTH-Aachen.DE[134.130.21.6]
Aug 10 11:30:02 b009 <info> postfix/smtpd[4418]: TLS connection 
established from b006.ika.RWTH-Aachen.DE[134.130.21.6]: TLSv1
 with cipher RC4-MD5 (128/128 bits)
Aug 10 11:30:02 b009 <warning> postfix/smtpd[4418]: warning: 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: SASL LOGIN authentication
 failed
Aug 10 11:30:03 b009 <info> postfix/smtpd[4418]: disconnect from 
b006.ika.RWTH-Aachen.DE[134.130.21.6]
Aug 10 11:30:21 b009 <info> postfix/smtpd[4419]: connection established
Aug 10 11:30:21 b009 <info> postfix/smtpd[4419]: master_notify: status 0
Aug 10 11:30:21 b009 <info> postfix/smtpd[4419]: name_mask: resource
Aug 10 11:30:21 b009 <info> postfix/smtpd[4419]: name_mask: software
Aug 10 11:30:21 b009 <info> postfix/smtpd[4419]: name_mask: noanonymous
Aug 10 11:32:21 b009 <warning> postfix/smtpd[4419]: warning: Read failed 
in network_biopair_interop with errno=0: num_read=0,
 want_read=5
Aug 10 11:32:21 b009 <info> postfix/smtpd[4419]: SSL_accept error from 
b006.ika.RWTH-Aachen.DE[134.130.21.6]: -1
Aug 10 11:32:21 b009 <info> postfix/smtpd[4419]: master_notify: status 1
Aug 10 11:32:21 b009 <info> postfix/smtpd[4419]: connection closed
Aug 10 11:32:21 b009 <info> postfix/smtpd[4419]: watchdog_stop: 0x82382f0
Aug 10 11:32:21 b009 <info> postfix/smtpd[4419]: watchdog_start: 0x82382f0
Aug 10 11:34:01 b009 <info> postfix/smtpd[4419]: idle timeout -- exiting

Does anybody know a solution to this Problem?

Regards
Jochem