mikew@bigboy.UUCP (Mike Wexler) (10/18/87)
About a month ago I posted a query about problems sending mail between various systems via ethernet. Following is a summary. After the summary I will describe my solution. The problem: We have a large(100+ node) Ethernet network. Some of the machines runing Xenix, some of the them running Unix SVR3, and some running 4.2BSD. Also we have two machines that talk to the outside world via uucp. What we want is to be able to send mail locally between machines, send mail to machines outside of Wyse(with auto-routing), and to receive mail from the outside world and distribute it. The solution: By the time the final solution is implemented, the two machines connected to the outside world will both be running 4.2BSD, sendnamil, and smail. Mail originating on one of these machines will be sent to sendmail. Send mail will determine if it is local(this machine), accesible via SMTP, or other. If the mail is local or accessible via SMTP, sendmail will deliver it. If the mail is other, sendmail will give the mail to smail. Smail then figures out a route to the machine(smail knows about local machines). Smail then calls a shell script called delivermail. Delivermail checks to see if the first host in the route is on the ethernet. If the host is on the Ethernet, deliver hosts uses rsh to execute rmail on the remote hosts. Otherwise, smail calls uux to deliver the mail. This part of the solution allows us to send, receive, or forward mail on the 4.2BSD based gateways. The 4.2BSD based non-gateway machines, can send mail to the gateways via SMTP, this can then be forwarded. The non 4.2BSD based machines, can send mail to the gateways via a machine Xenix based machine, that can forward the mail to the gateways via UUCP. Another possible solution: I would have a many UAs(User Agents, mail, mailx, GNU mail, etc.) a mail parser(sendmail without SMTP), a router, and a TA(transport agent) for each type of communication protocol. 1. User agents: There are plenty of user agents available and users will pick there own, the only problem is that some of them(System V /bin/mail and /bin/mailx) don't allow me to specify how to deliver mail. Please correct me if I'm wrong here.. 2. Parsers: For a parser, sendmail is adequate, but shouldn't really have SMTP built into it and could have a friendlier syntax. 3. Routers: For a router, smail is adequate except for one deficiency, it doesn't generate a transfer agent(I know it was intended to be used for UUCP mail only). 4. Transfer agents: For uucp, rmail is a reasonable transfer agent. Unfortunately there is no program that allows me to transmit mail via SMTP over Ethernet. I know sendmail can do this, but I get into recursion problems. Also it is more difficult to port and maintain as one monolith rather than several smaller prorgrams. What I would like is a program that sends SMTP mail and a daemon that receives SMTP mail. If anyone knows of such a program, please tell me. Another possible solution: This solution is a combination of the first two. In this solution, sendmail would parse the address. It would then call smail which would route it. The sendmail would be called with a different configuration file. It would then deliver SMTP mail, deliver local mail, or call uux/rmail for UUCP based mail. -- Mike Wexler UUCP: wyse!mike ATT: (408)433-1000 x 1330