On my next hike I plan to use a Postholer journal and they have a slick way to update your journal via email, including updating a Google map, using coordinates in a properly formatted email. That only works for trails they have a map for, however, so it won't work for me on this hike.
I'd like to figure out a way to do something similar via email or ideally a text message from the boonies. What are the options? I want to do it via mobile phone, not a Spot.