Winlink …a worldwide amateur radio email service
that uses radio pathways where the internet is not present, and is capable of operating completely without the internet–automatically–using smart-network radio relays. https://winlink.org/
Easy Steps: learn a little about Winlink, without using an amateur radio:
Winlink Without Radio, by Bill Thomassen N6NBN (March 2019)
…and now with a radio:
Introduction to Winlink: Email Over Radio (N6NBN) (Feb. 2018)
For a good local source of additional information see:
https://wiki.psrg.org/wiki/Winlink:_Internet_Email_over_Radio