I did find this thread, but it refers to settings that I don't see, specifically Setup -> Email -> Incoming Email. We have Incoming Email Accounts, but there's no option there having to do with HTML.
We have an issue-tracking system, called PITS, setup to automatically open tickets in our Web Help Desk by sending email, and we'd like those emails to include a link back to PITS. However, the links in the email are stripped out and the Web Help Desk seems to recognize the word "incident" and replaces our link to PITS with a link to a non-existent Web Help Desk ticket with the PITS incident number.
We'd like to have incoming HTML, especially links, left in so our users can access them. Is this possible?
I figured it out: you don't put any HTML around it and just put the link in as plain-text, like https://berkeleypubliclibrary.org/ and WHD will convert that to a link for you.