On Mon, Sep 20, 2021 at 07:16:27AM -0400, The Wanderer wrote: > On 2021-09-20 at 03:21, David Christensen wrote: > > > Your message displays strangely on Thunderbird (oversized Courier > > font?). > > In my case, it displays with unusually-small characters and what looks > like a different font, not unusually large ones.
The original mail consists of two base64-encoded blobs of content. If you "base64 -d" the second blob, it's not even a fully proper HTML document. There are no initial <html> headers or anything. It simply begins with some lowercase English text, then <br><div> and another line of text, </div><div> and a third line, and so on. How your HTML-based mail user agent responds to that will depend on the decisions made by its authors.