How are you sending out emails?

[William]

I didn't realize there was a font issue with Thunderbird. That would preclude me from using it as I need larger fonts with everything unless I use a magnifying glass.

You can't change the font size of menus and labels.  I tried about:config and modify layout.css.devPixelsPerPx, but it only change the spacing between the chars, not the actual size of font.  But, it helps a bit, because chars are not stuck to together.

I'm also curious, Bill, you can get your Yahoo mail via Thunderbird? Do they have a POP3/IMAP server without having to pay for the premium edition? Maybe I'm just stuck back in the 2000s when you needed one to get that feature.

Yes, I always used and am using POP3/IMAP/SMTP from Yahoo.ca, no premium plan.