I've got around 20 domains on different mail servers (postfix, exchange, gmail etc) and want to forward all of them into a local Zimbra email server (with dyndns dynamic domain) in order to give my users sharing options for calendar & contacts. Users must be able to send email through Zimbra by using each of the domains SMTP.
Is there a way to handle this scenario?
I've read about relay in the Wiki but it contains information only for single smtp/domain.
Any help is much appreciated.