auth error squirrelmail

[justin]

Hello,

I have squirrel mail installed only i can not log in.
The error message i recieve is like this:

Bad request: The IMAP server is reporting that plain text logins are 
disabled. Using CRAM-MD5 or DIGEST-MD5 authentication instead may work. 
Also, the use of TLS may allow SquirrelMail to login. Please contact your 
system administrator and report this error.

I`m using imap-uw server and i have no idee where to change these options.
Maybe someone can help me where to look.

Thanks,
Justin.