Empty HTML tags end of each line of HTML email

Since updating to 4.4.2 (and updating all of my CPAN modules at the same time), when an Outlook user send an email to open a new ticket, I see “<>” at the end of each line when I look at the ticket in RT.

Ticket/Attachment/WithHeaders shows a body like this:

Which gets rendered in RT as this:
test 3<>

Instead of just “test 3”.

Any ideas on where to start troubleshooting this?