i use mutt to send customers mail with attachments, works fine, but the problem i have is when customer receives automated message it is from root@blah.com
i need it to say from customerservice@blah.com so if they reply it goes to customer service and not root.
does anyone know where or what in the .muttrc file or sendmail config file I must change to masquerade as a customerservice@blah.com.?

Masquerading is cumbersome even in sendmail. Does su to customerservice not work? I've never tried.

The reason for not trying is sendEmail:
If you are not totally bound to mutt consider using a well-tested app that does a lot of mail sending very well, IMO: sendEmail. masquerading is easy.
Software :: SendEmail - Send email with this free command line email client

FWIW - This may sound trite, but running an everyday app under root is normally not an idea to consider.

Actually, masquerading is not really very hard at all, but you have to know what you are doing. Do you want just the From: line to be correct? Or also the Sender:? Or also the Return-Path:? All of these can be done but we don't want to tell the spammers in too much detail how to do it.

I suggest that you find this file: Mutt+msmtp.txt and follow the directions

Good luck

You Can use the below format:

Create an real name for the mail id => 'customerservice@blah.com' for time beinng i called 'customerservice'.

mutt -nx -e 'set from=customerservice@blah.com; set realname="customerservice"' -s "Mail Subject" -a attachment_file customermail_id

its working for me. try it...

Good Luck.