My off-the-cuff guess is somehow Outlook is munging the email headers:
Each line should immediately follow the next, and they should have the
same HEADERTYPE[COLON]HEADERCONTENT format.

But Outlook is putting some email references in the middle of them,
which do not follow that format shown above, and because every
email-reader expects an empty line at the end of the headers, they
display what follows as though it were the content of your email, and
not more headers. Either that or something along the route between you
and the vanagon mail server is munging the headers, but I sorta doubt
that or they'd be getting a lot of attention from outlook users and
their servicer providers.

I don't use Outlook, so I can't say what you may do to stop that
behavior, but it's possible there is a setting to stop or start
tracking conversations, or however outlook sorts mail, that might be
toggled to stop the behavior.  The mail reference IDs are where it's
messing up.

> I hesitate to comment on the list due to this problem, but I'm not sure
> what's causing it. I am simply using outlook...no word processors, no other
> funky stuff like that. Just straight up Outlook.
>
> Can someone explain to me how to change my email address to see if that
> helps?

--
It seems my TO-DO list is a FITO (faster-in-than-out)