J.R0wan > wrote:
> The customer only wants the host name, not the fqdn as two companies are
> having email sent out, the identity of the new company (sales@fqdn2.com)
> needs to be different from the identity of the existing company which
> shows in the header below as pegasus.fqdn.com.
>
> The customer just wants the hostname, pegasus rather than the
> pegasus.fqdn.com.

So be it.

Add the following line to your sendmail.mc file and generate a new
sendmail.cf.

MASQUERADE_AS(`pegasus')dnl

This should be placed somewhere in the middle of your sendmail.mc,
before the "MAILER" lines.
This will rewrite all occurrences of the sender address in the message
headers. If you also want to rewrite the envelope sender add also
the line:

FEATURE(`masquerade_envelop')dnl

Finally, if local recipient addresses in the message headers should
also be rewritten, you should also use:

FEATURE(`allmasquerade')dnl

This will do what you asked for. I'm not sure if the effect is what
you expect it to be. I'm quite sure this will need special processing
at the receiving end, but maybe has your customer such special
processing configured.
In short:
-- external mail servers, without special configuration, will reject
your messages because the sender is invalid.
-- internal relays or receiving servers, without special configuration,
will either reject the invalid sender address or recognize the
host name and convert it to a FQDN. :-(


A final note: using MASQUERADE_AS will masquerade all mail origin
from your server, even output of cron jobs and things like that.
It is possible to apply such rewriting to a limited set of sender
addresses. Look for 'genericstable' in cf/README if you want to do
so, and just ask for if you need with that.
The need for special handling of your messages at the receiving end
will be the same as mentioned above if you decide to use
'genericstable', for you'll still be generating invalid sender
addresses.


Regards,

Kees.

--
Kees Theunissen.