[Mailman-Users] Why are footers sent as attachments?

[Jp Possenti]

Why is it that when I set Mailman to apply a footer with some info, Outlook
detects it as an attachment?
Is this yet another problem with just outlook?
 
Also does the footer in mailman support HTML?
 
I want to make it so at the bottom of every email I can include a reply to
address for them to unsubscribe.
 
This sort of leads me to my next question.
 
To have a user unsubscribe without seeing the web interface and just by
email, which would be the right command?
 
Listname-leave at domain.com
List-unsubscribe at domain.com
 
 
Or are there more?
Also does anything need to be written in the subject line? If not, what if
someone writes something or writes something that is not right, will it
still unsubscribe them?
 
I would like to state that if they want to be removed, to please "click
here" to send an email to unsubscribe.
 
 
Kind regards,
 
Jp