The BBS handles Messages with a Message Type of 'T', which are normally used for NTS messages, rather differently than 'P' or 'B' messages.
They can be read by any user, and a commnand "Delivered" (which can be abbrieviated to D) can by used to set the message status to 'D'
A typical NTS address would be zipcode@NTS(State) - eg 12345@NTSCA
You can specify a partial match on the TO field.
12345 will match a TO of 12345
123* will match any TO starting with 123
* will match any T type message.
The code will forward a message to the BBS with the longest match. So if one bbs has 12* and another 123* , 12345 will go to the second. 12400 will go to the first.
It will only route on the AT field if there are no matches on TO.
NTS messages can be input via the SMTP interface. If an SMTP messages is received with a TO address of format nnnnn@ntsxx, or email@example.com, it will be treated as an NTS message. The latter format is needed by some email clients (eg Outlook Express) which don't allow addresses without a . in them. The trailing .nts will be removed.