Hi all, Ryan suggested to create a SUMO article for this. Since I don't have rights to create articles at SUMO, I wrote it up in the Wiki. Foolishly I chose a URL with a dot at the end and linkify excludes the dot to clicking on the link doesn't work in plaintext e-mail. But for the archives, plaintext is preferred. Here's the link: https://wiki.mozilla.org/User:Jorgk/8-bit_bytes_and_e-mail_corruption_at_Verizon,_Yahoo,_etc. Paste it into a browser, including the dot a the end. Volunteers for the SUMO article? Jörg.