Simple one-size for printing, emailing, social media

[jon404]

First, good to see this forum still going. Retired now, doing tourism development in Tombstone Arizona.
Discovered that if I make a 200 dpi JPG from a standard 8.5x11 letter page, the resulting 1700 x 2200 image will print just fine when emailed to someone, and also display correctly on Facebook or Instagram.
This saves me from having to bother with PDFs failing to embed unknown fonts, or having to deal with the CMYK - RGB color thing (longtime note: Mike Wenz is the only person who understands Xara color). perhaps like you, I alwats try to push the printing burden onto my JPG viewers -- and 200 dpi comes out surprisingly well on most printers while keeping the email filesize low. Give it a try!
Lastly, seems like everyone is getting all their info off smartphone screens these days... so I'm designing my tourism poster-JPGs to be readable on an Apple iPhone 8, which works for others as well...