[Mimedefang] Reserved Connections from Loopback

[Kevin A. McGrail]

You *can* (probably) change Mailman to utilize sendmail -odd directly by 
editing Defaults.py and changing the Handler:

DELIVERY_MODULE = 'SMTPDirect' to 'Sendmail'

However, it has this lovely caveat:

# WARNING: Sendmail has security holes and should be avoided.  In fact, you
# must read the Mailman/Handlers/Sendmail.py file before it will work for
# you.

And warnings in the handler like: 'Use of the Sendmail.py delivery module is 
highly discouraged'

But the fun doesn't stop there:

SECURITY WARNING: Because this module uses os.popen(), it goes through the
shell.  This module does not scan the arguments for potential exploits and 
so
it should be considered unsafe for production use.  For performance reasons,
it's not recommended either -- use the SMTPDirect delivery module instead,
even if you're using the sendmail MTA.

DUPLICATES WARNING: Using this module can cause duplicates to be delivered 
to
your membership, depending on your MTA!  E.g. It is known that if you're 
using
the sendmail MTA, and if a message contains a single dot on a line by 
itself,
your list members will receive many duplicates.


At the moment, I've switched to using port 587 on the MSA and I've changed 
the MSA to exclude Mailman from reverse DNS checks.  I've not used the MSA 
much except for some of the MIMEDefang administrative notices & stream_by_ 
routines so I don't know if it will have the same connection limits.  I also 
not 100% sure this is a good idea but it seems sane enough.

KAM

> Can you not configure Mailman to invoke Sendmail in deferred mode
> ("sendmail -odd ...") so the mail just goes into the clientmqueue and gets
> picked up by the next clientmqueue run?