please help: trouble logging into pop3 with postfix & dovecot

[the block]

I am doing a project for a linux class in college. My goal is to build a linux email server, and I am using postfix and dovecot. Everything seems to be going well, but I have run across a problem. I am trying to log into my pop3 on dovecot with outlook express. I have my user and pw typed in correctly, and it keeps asking me for my user and password.

This is the error outlook express gives me:

There was a problem logging onto your mail server. Your User Name was rejected. Account: 'postfix.cita430.com', Server: 'postfix.cita430.com', Protocol: POP3, Server Response: '-ERR Plaintext authentication disabled.', Port: 110, Secure(SSL): No, Server Error: 0x800CCC90, Error Number: 0x800CCC91

I picked out the "-ERR Plaintext authentication disabled." error because I figured it had something to do with that. I went into my /etc/dovecot/dovecot.conf file and found where it said "#disable_plaintext_auth = yes", I uncommented it and changed the yes to no so it read "disable_plaintext_auth = no", and tried again to log into pop3 with outlook express.

Now there is a new error and it says:
Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Account: 'postfix.cita430.com', Server: 'postfix.cita430.com', Protocol: POP3, Port: 110, Secure(SSL): No, Error Number: 0x800CCC0F

I have since changed it back the way it was since I seemed to be getting better results with it, well atleast A RESULT (where it would ask me for my user name and password repeatedly). I am pretty lost. I have been researching this for hours on the web and haven't had much luck, so I figured I'd make an account on this forum and ask here.

I would appreciate any and all help that anyone would be willing to throw my way. I don't think this is something too terribly complex, I am just new to this and haven't quite got it figured out yet.

[falko]

First you must enable the plaintext authentication again. Then check your mail log for errors and post them here.
Which distribution do you use?

[the block]

Originally Posted by falko

First you must enable the plaintext authentication again. Then check your mail log for errors and post them here.
Which distribution do you use?

Hi falko, thanks for the reply. I am using Ubuntu Server 6.10. I will enable plaintext authentication again, try to log in with outlook, and then post my mail log. I won't be in the computer lab until about 1:45pm EST, but please check back with me and see if my log gives you any ideas. Thanks again.