Problem with exim + mailscanner

[Javier Martinez]

I have a problem sending email. 

I'm getting some of this:

  Delay reason: Connection timed out:
    SMTP timeout while connected to fisica.ufpr.br [200.17.209.129] after MAIL
FROM:<here at fisica.unam.mx> SIZE=4194
  to at fisica.ufpr.br
    Delay reason: Connection timed out:
    SMTP timeout while connected to fisica.ufpr.br [200.17.209.129] after MAIL
FROM:<here at fisica.unam.mx> SIZE=4194

and my logs:

1GNurc-00047n-1J == to at fisica.ufpr.br R=dnslookup T=remote_smtp defer (110): Connection timed out: SMTP timeout while connected to fisica.ufpr.br
[200.17.209.129] after MAIL FROM:<here at fisica.unam.mx> SIZE=3008

I googled and I couldn't find a solution to my problem, I'm having this problem with a couple of hosts but my connection is working ok.

Thanks a lot.

Javier Martinez