Walker,
I sent you an IM to try and keep the clutter down.
No matter how I read this, to me, it comes out this way:
Avast seems to have trouble reading the "." in the middle of the username.
I fell that "walker#pop3.terra.es" is correct.
Also, shouldn't the DefaultSMTPServer=Smtp.terra.es?
Also, this bit of confusion comes from Avast:
Since your e-mail program supports SMTP authentication and also makes it possible to set a different login name for SMTP than for POP:
If the SMTP authentication is enabled, append the character # and the address of your SMTP server to the login name (e.g. walker#smtp.terra.es).
If the SMTP authentication is disabled, enable it and use the character # together with the address of your SMTP server as the login name (e.g. #smtp.terra.es).
Boy, this is getting really confusing!

Don't you have a normal domain name that you can manually configure in Avast and test?
Frankly, I am running out of ideas. If the email fails, look at the Internet log you activated. Yes, I agree it may slow the system down a
bit, but nothing major. If the log saves ALL activity throughout the mail process, then it will put on the brakes a little. You would expect that from any subroutine that is pulling in more information.
Anyway, let me know what the log shows. Maybe Technical's tests will give some insight.
Nite,
techie