Control over senders domain name

Hi all

Early days for me and linux email so please bare with me....

I've inherited two servers, one running sendmail, one running postfix.

I want to control the domain name that is appended to the senders name
when sending email via sendmail/postfix from the command line. This
will allow me more control over how these emails are filtered by a spam
and email signature engine.

Using the command
echo "test body" | mail -s "Test email" me@mydomain.com

two different sender email addresses are visible in the received email.
On the sendmail server the senders name appears in my inbox as
root@servername.local whereas on the postfix server the senders name
appears as root@servername.mydomain.com.

I'd like to standardise and have servername.mydomain.com replaced by
servername.local.

Could anyone point me in the right direction? Is this something
controlled by the postfix/sendmail config or is it within the network
config itself?

Also, how does the mail command know to use sendmail or postfix? In the
medium term I'd like to install postfix on the sendmail box as I've
heard it's simpler to configure. Is there a way for these two packages
to co-exist so the transfer to postfix can be as risk free as possible?

Many thanks
StevieH

Davide

Thanks. "Rewrite" was the key word I was looking for, move along now.

The sendmail info was most useful. It appears that the issue I was
having with .local was due to differences in /etc/hosts, rather than
differences in the postfix/sendmail rewrite config.

This is easily visible using the hostname -v -f command.

StevieH