Same account for mailbox and forwarding

Sorin Gitlan 9 years ago updated 9 years ago 5
There is an option in cPanel and Virtualmin (maybe in others also) where you could
create a mailbox and a forwarding for the same account.

All mail sent to test@example.com is saved into that mailbox but it is also
forwarded to another email account like testing@gmail.com 

This would be a very useful function for those who want to keep a backup for the received emails
but use Gmail for example to aggregate multiple email accounts.

It doesn't seem to work.
If I have a mailbox:  sorin@example.com I can't add a forward account with the same sorin@example.com mail.
Made 2 tests and all mail delivered. (Though with a 3 minute latency, maybe something with the networks).
Thank you!!