[exim] alias, mailer transport, rewriting....

I'm looking at a number of MTAs to replace our current SMTP cluster and had
some questions about the way Exim handles aliasing and address rewriting.
Our current system does something like this:

- Email comes in for michaeln@???
- An alias lookup is performed and finds that michaeln@??? points
to michael2812
- A transport lookup is also performed and finds that michael2812 goes to
server8.test.spam
- The MTA then sends to the email to the specified server as just
"michael2812"

e.g.
RCPT TO:<michael2812>

I've found that other MTAs will not send an email without a domain name
attached to the end. Will Exim let me do this? Will Exim let me setup a
system as I've described above?

What some MTAs do is the following:

- Email comes in for michaeln@???
- An alias lookup is performed and finds that michaeln@??? points
to michael2812
- A transport lookup is also performed and finds that michael2812 goes to
server8.test.spam
- The MTA then sends to the email to the specified server as
michael2812@???

The idea is that I would like to assemble a new cluster to handle SMTP tasks
that will appear transparent to the other parts of the current system.

Thanks in advance. ;-)


Michael