I don't pay enough attention to e-mail notifications any more, since I
no longer get alerts for them on my phone. I do get Matrix
notifications, though, through Element, and that seems to work well as a
reminder for me.
Matrix is of course a lot more complex than e-mail. It is a stateful
protocol that requires (at least) keeping authentication and/or session
information on the client. Technically, clients all have a "device ID,"
which they should use any time they communicate with the server. I
decided it makes the most sense to keep this value in the same cache
file as the filesystem UUIDs and timestamps. I prefer reading usernames
and passwords from a configuration file over passing them as
command-line arguments, so I added that ability as well.
Dustin