No AUTH PLAIN with dovecot 2.0.19

Hi

I have installed the package dovecot-postfix on Ubuntu 12.04 LTS:

dovecot --version: 2.0.19 postconf -d | grep version: 2.9.6

and receiving email works very fine, but relaying email does not work.

I think the problem is that after STARTTLS the authentication is not being executed

250-AUTH PLAIN 250-AUTH=PLAIN

which means using telnet returns

telnet mx2.wyona.com 587 Trying 50.116.54.197... Connected to node3.wyona.com. Escape character is '^]'. 220 node3.members.linode.com ESMTP Postfix (Ubuntu) EHLO letscallitevil.com 250-node3.members.linode.com 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-STARTTLS 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN

So far I have used dovecot version 1.2.9, which works very fine, but the configuration

/etc/dovecot/dovecot.conf

seems to be very different in the case of dovecot version 2.0.19.

I have checked all kind of tutorials for several days now, like for example

https://help.ubuntu.com/10.04/serverguide/postfix.html

but nothing helped.

Any pointers or help is very much appreciated.

Thanks

Michael