Outlook sending message multiple times and generating error message

[Diane Simpson-Bundy]

In the last week, I've been sending out emails, and they get sent to
the recipient, but Outlook generates an unspecific error message (with
no description, or error message, or anything). Then it sends the
email 1, 2 or maybe more times anyways, but it stays in the outbox as
well. Anyone have any ideas? Thanks.

Diane