> Is there a GUI overlay for paclink-unix?

Yes there is a web Interface to paclink-unix transports.  It looks
pretty clunky as I am in no way a 'gui guy' but it does work & has been
around for a number of years.

The default install of paclink-unix now installs that interface with
BETA9.
./app_config.sh plu

You can see what it looks like by going here & scrolling down to
'Test PLU web interface'

https://github.com/nwdigitalradio/n7nix/blob/master/plu/PACLINK-UNIX-IMAP_INSTALL.md

After ./app_config.sh plu you can bring up the interface in a browser
with this url:
locally: localhost:8082
same network subnet different computer: <ip_address_of_your_RPi>:8082

The rest of the notes in this file are obsolete as they are already done
in the standard plu install script. The pluimap install is currently
under destruction and my intention is to make it the WiFi email app use
case with the RPi acting as a host Access Point.

> And is there a timer function so that it checks to send / receive
> every X minutes / hours (operating under the premise that the Gateway
> is up, stable and active).

This would be very easy to set up with a cron job as all the
paclink-unix functions are run from the console or script.

/Basil n7nix