[imp] SMTP error messages when using the smtp mailer

[Per Steinar Iversen]

IMP is not very informative when using the smtp mailer and the messages 
are rejected by the mailserver. For example, if the test-message eicar.com 
is sent then the mailserver return "554 5.7.1 Virus..." after the SMTP 
DATA command has finished and this is reported by IMP as "There was an 
error sending your message: unable to send data"

Is it possible to make IMP report in more detail the message from the 
mailserver? This would for example be helpful for those trying to mail a 
virus infected document.

-psi