Good catch, Grant. They are GET requests. Our developers implemented the
List-Unsubscribe HTTP method a long time ago and it appears that it was never
updated to comply with RFC 8058. I'm still curious as to why I'm only seeing
this with .edu domains hosted on Office365 and not Office365 in general
(perhaps different filtering techniques are used for Universities?), but the
fix is clearly to have our developers fix the header.
mailop mailing list