block emails with Fetchmail...

[jdow]

From: "Paul Howarth" <paul at city-fan.org>

> Kostas Sfakiotakis wrote:
>>> Sendmail uses it for local mail delivery by default on Fedora, and it
>>> can also be used to deliver mail by fetchmail if you like.
>>>   
>> 
>> Am not sure that i fully understand that . Fetchmail fetches email from 
>> the remote POP3 Server
>> then it alters the To address as to make it suitable for local delivery 
>> . Then it passes the email to
>> sendmail . Now sendmail tricked by the altered To address believes that 
>> the email is for local
>> delivery and for that reason it passes the email to the local mailer as 
>> defined in sendmail.cf /
>> sendmail.mc , which in Fedora installations is procmail .
> 
> Sendmail isn't "tricked" by the altered "To:" address; what fetchmail 
> has done is to forward the mail to a new (local) address. All sendmail 
> is doing is delivering the mail just as it would for any other mail it 
> was handling.
> 
> Fetchmail doesn't have to work this way though. If you use fetchmail's 
> "mda" option, it can invoke procmail directly and not use sendmail at all.

"mda" is very often the better way to do it. Working the other way
often leads into two passes through something like procmail and
SpamAssassin. Two passes through SpamAssassin can lead to messed up
spam scoring. That's generally a very bad thing if proper spam
scoring counts for you.

{^_-}