Using Mutt from scripts

[Scott Alexander]

Hi,

I'm new to using Mutt and I wanted to use it to send mail from a web 
page.

I can send a message including an attachment. 

I've used a header file to set the From: field but how important are 
the message id's. CAn I just create a message id?

Or is there an easier way or setting the From: field. The web page is 
used by about 600 users so each time the From field will be 
different.

I'd be pleased to hear from anyone who has had experience with this. 

regards

Scott