Have Exchange 2010 with multiple accepted domains, 1 AD forest. Some users need multiple e-mail accounts with Send As feature, with different domains.
Have BES Express 5 too.
I'm very interested how you run similar environments in your organizations. Do you create 2nd AD user with different naming structure or just mail contact? Do you just create POP account? How you set this us on Blackberries etc.
Thanks in advance.