[CentOS] dumb sendmail question -- how to get outbound messages to use "example.com" instead of hostname?

[Kenneth Porter]

On Monday, July 02, 2007 10:14 PM +0100 Steve Searle 
<steve at stevesearle.com> wrote:

> Are you talking about what appears on the "from" header line.

What's important here is the HELO/EHLO name. That's what the receiving MTA 
will use to check against your reverse DNS.

The "envelope from" specified in the MAIL FROM command comes from the 
message from the MUA. This is the part that can be masqueraded.