From "gsmctl -h"
-S -l, --sms --list <TYPE> List SMS by type [all, read, new]
I take it that there should be a difference between "all, read and new" SMS in the list. But all SMS are marked as read at delivery / receiving. So using the term [new] will never work.
To replicate:
1. Sending an SMS to my cell phone.
root@Teltonika-RUTX11:~# gsmctl -S -s "((withheld cell number)) Foo Bar, this is a test"
OK
2. Send a reply from my cell phone to the routers SIM / number.
3. Without reading it, list the received SMS's
root@Teltonika-RUTX11:~# gsmctl -S -l all
Index: 1
Date: 2021-10-30 05:42:49
Sender: ((withheld cell number))
Text: Received
Status: read
------------------------------
As shown, the message already are shown as read. This is making it difficult to write script aimed towards undrad messages only. It's still doable, but having this issue fixed would be great as I'm heavily dependent on scripting my router for answering SMS's.