Forum Discussion
By now I never recommended to balance incoming SMTP via link controller.
You can use priorities for your MX records and control it that way.
So for incoming mail you will have additional virtual servers to handle the related protocols.
At the same time SMTP has it´s build in redundancy. That´s why I don´t see a real need to use the link controller functionality for this task.
One thing to take care of is to SNAT outgoing mail traffic with the IP addresses associated with your MX records. Why? In case a reverse lookup is made at the receiving mail gateway it better points to an MX record.
To accomplish this, you will have protocol specific wildcard virtual servers for outbound traffic combined with a SNAT pool. SNAT pool members will be the virtual IP addresses for incoming mail.