[Mailman-Users] Subscribing by email?

[Paul Key]

Mailman 2.1.3
Solaris 9

Hi

I am looking to get users to subscribe and unsubscribe from certain 
lists using email.  I am getting them to emal 
<listname>-request at blah.blah with "subscribe" in the message body. This 
works fine with an empty subject field (they get one confirmation email 
as expected) but if they put a subject on the subscription request email 
they receive two subscription confirmation emails from mailman in reply. 
Anyone no why this happens?  They would like to put something in the 
subject.

Also does mailman 2.1.3 support the sending of a blank email to 
<listname>-subscribe at blah.blah ? (or some similar address) instead of 
the subscribe email via request?

Thanks

Paul