Changing default from e-mail address for system accounts when using sendmail

I ran into this recently.

You can change the address with the generic maps as davidgo mentioned.

In /etc/postfix/main.cf

Add this line

smtp_generic_maps = hash:/etc/postfix/generic

And then in /etc/postfix/generic
Add the line for the originating email address, and the email address you want it to appear to be from

[email protected] [email protected]
[email protected] [email protected]

and then run the following postmap command to re-generate the map:

 postmap /etc/postfix/generic

To make the user appear to be Example Company you need to set the GECOS field in /etc/passwd for root and www-data to be Example Company