A client is changing their primary domain name and company name, but
wants to retain the existing domain. Essentially this should function
as if the domain names were just alternate names, i.e.
"user@mycompany.net" is the same as "user@mycompany.com" without,
hopefully, separate administration needed.

I'm looking for the best way to do this while keeping the administration

I feel like I'd seen some facility for an alternate domain name in
Groupwise, but I can't quite recall enough about it to proceed with
confidence. Note that while I want all mail for both domains to arrive
& be visible for each user, I want the domain names relatively
transparent from inside the company.

Any suggestions as to the best way to do this?

-- DE