He would return the identification strip when she signed for the outgoing mail.
"Besides, people can always leave outgoing mail in their own mailboxes."
I saw a lot of his outgoing mail with the agency name on the envelopes.
I could see a pile of envelopes tucked in the box for outgoing mail.
He takes his outgoing mail to the post office.
He passed across the outgoing mail, but held a large, red, oversized envelope.
Examples of solo usage are most often found on outgoing international mail.
Our mailbox has a different place to put outgoing mail.
With luck, it would look like a piece of outgoing mail.
Areas of responsibility include maintaining office files and input data from outgoing mail.