domain alias as sender

[coreASP]

Does Postfix/Zimbra's MTA allow for domain aliases to be set as the default sending username@domainalias.com

We have a user who has user1@domain1.com and user1@domain2.com both receiving to the same domain as a domain alias, however one user in particular needs to send out under their domain alias.

Any ideas?

thanks,

[KevinH]

Not possible unless you provision them as the alias and then make the other email the alias.