Email - Multiple aliasses, identities and forwards - suggestions?

Addendum, for the case someone stumbles on this thread later on.

I had a situation where I wanted an identity to reply to forwarded mail from a group account. I could not add the other account to my mailclient, as it was an LDAP-group, not a user account with a mailbox.

The reason for using the group account was to have mail aliases that could distribute mail to a number of recipients. My account is one of those recipients. If it does not work for you, check your Postfix configuration and edit if needed.