I have zimbra 8 FOSS installation and internal domain mail.local. External mail is received with external accounts in user
preferences. Each user has another persona with external email (e.g. @mail1.com) -
each user has two addresses, i.e firstname.lastname@example.org and email@example.com.
@mail.local is for confidential internal mails.
Is it way to prevent outgoing mail from addresses @mail.local to any address except @mail.local, but permit @mail1.com to any addresses ?
firstname.lastname@example.org -> email@example.com --- may cause an error or delivery failure message
firstname.lastname@example.org -> email@example.com --- everything OK
firstname.lastname@example.org -> email@example.com --- everything OK