This is just odd.
I don't check my mailbox at Dominican often, so I have it forwarded to an e-mail address I do check -- using the procedure described by Dominican's IT department.
They just upgraded their spam filter.
The spam filter checks for OUTGOING spam as well.
It's now catching some of the mail I'm forwarding FROM that account TO my yahoo account.
What it's particularly likely to catch as spam are the daily e-mail notifications they send out telling you that you've received spam! There's an example below.
This seems to set up some sort of spam generating / spam catching feedback loop, although since it only generates one message a day that's not too bad.