Dear Falko, thanks for replying.
I have tryed, and it just works
Now the situation is:
I use Amavis and from what I have understand If some person sends me an email from the internet it will be received by Postfix on default port 25; If Postfix accepts the email it will be forwarded to amavis on TCP port 10024 (SMTP); then if amavis considers the mail ok it will send the mail back to Postfix on TCP port 10025.
Finally postfix delivers the email to the actual recipient.
Do I have to set/change something with antispam/antivirus, because now e-mails arrives from fetchmail and not "directly" to the mail server or all is ok?
Thanks in advance.