Diagnose "Mail Round Trip" checks the mail flow and the duration of an e-mail.
In this case, an email will be generated and sent to an external Reddoxx roundtrip portal.
Sender is the appliance address.
In return, the email will be sent back to the sender address. Then the diagnosis evaluates the duration and success of delivery.
This Diagnose is only suitable for SMTP Environments and will not work in POP3 Mode.