SMTP traffic loadbalancing originating from one IP - possible packet loss?

another concern is what if one of the james mail server nodes crashes during a message transmission, then f5 would redirect it to another node, which is not aware of this message. How will smpt relay react to that?

 

seems when balancing via MX this is not an issue, as it has its own standard mechanism of resending messages and adding failed messages back into the queue in order to resend later.