[CentOS] slow SMTP-AUTH

Hi,

	I installed sendmail on a centos-4 openvz VM.  I set up SMTP-AUTH and 
when I try to send mail using this server, there is a big delay in which 
my e-mail client (Mozilla Thunderbird) just hangs.  The server, on the 
other hand, is idle at the same time.  It does that no matter if I use 
no encryption, TLS, or SSL.  When the client is 'hung' sendmail, on the 
server side haven't logged anything yet for this connection.

Any idea?

Regards,

Ugo