The packet radio bulletin board has some of that capability but is accessed via ham radio. The bulletin boards share public messages (bulletins) and take care of forwarding messages between one another. A ham can connect to one bulletin board, leave a message for a friend at a distant board, and have that message moved to the bulletin board of the friend. It is pretty easy to check the local bulletin board and see if you have any incoming messages.
As of September 2017, the TARPN management scripts enable any node op to turn on a bulletin board on their node. The G8BPQ package includes a system which is pretty easy to administer.
WNDHM2:K1TR-2} Connected to BBSDSW:WB1DSW-1 [RLI-19.13-HIX$] WB1DSW - 2 Users> lm Msg# Stat Size To From Where Date/Time Subject 12508 P 868 KA2DEW WB1DSW 1101/1019 re: 386 WB1DSW - 2 Users> r 12508 Date: Sun, 01 Nov 98 10:19:51 EST Message-ID: <12508@WB1DSW> (12508@WB1DSW) From: WB1DSW@WB1DSW.NH.USA.NOAM To: KA2DEW Subject: re: 386 Path: WB1DSW KA2DEW wrote to WB1DSW on Sat Oct 31 23:30:32 1998: > Yes, > the machine with the mono monitor will work perfectly. 2 serial ports > is good. One will run to the 9600 baud port and the other backbone RF, the > other to the BBS TNC and to the user port, or something like that. > Are any of your TNCs capable of 38.4Kbaud on the serial port? No - all TNC's here off the matrix are at 9K6. Never bothered to upgrade - didn't make any sense. > > We still need another computer for Ed. I will call him on the phone tomorrow. > He's going to need 2 or 3 serial ports. > > Tadd I'm pretty sure he's got at least one '386 over there - perhaps from the contest station prior to my purch of the '486... 73 de Herb WB1DSW.FN42LV.NH.USA.NOAM (NEGate) or firstname.lastname@example.org WB1DSW - 2 Users> *** Timeout. WNDHM2:K1TR-2} Reconnected to WNDHM2:K1TR-2 *** DISCONNECTED [11/01/98 12:05:27] cmd:c wndhm2 *** CONNECTED to WNDHM2 [11/01/98 12:31:37] c bbsdsw WNDHM2:K1TR-2} Connected to BBSDSW:WB1DSW-1 [RLI-19.13-HIX$] WB1DSW - 4 Users> sp wb1dsw Sj: Ed FlexNet on old 8088 PC Enter message. Control-z (or /EX) to end, it will be message 12535 I talked to Ed. I'm going to see him later in the week and I'm going to give him what he needs to put FlexNET on his old 8088. He's going to run that at his user station with one 6pack TNC. We're going to look for an additional serial port card for that PC so it can have 4 serial ports. There is a computer show at Rockingham park later this month. I think it's Nov 21. www.ncshows.com has the latest scoop. More later Tadd /ex Message to WB1DSW accepted. WB1DSW - 3 Users> b WNDHM2:K1TR-2} Reconnected to WNDHM2:K1TR-2 *** DISCONNECTED [11/01/98 12:48:38] cmd: