Why can my BBS receive Internet e-mail or inter-BBS instant messages?
You must have the Synchronet SMTP (mail) server running and listening for incoming connections on TCP port 25 (the standard SMTP port). You (or a friend) can test this basic connectivity by attempting to Telnet to port 25 (instead of port 23) at your BBS’s hostname or public IP address from a remote location on the Internet. The remote Telnet client should see a successful connection and a text message similar to the following: 220 bbs.synchro.net Synchronet SMTP Server 1.362-Win32 Ready You should also see evidence of the successful SMTP connection to the server in your Synchronet Mail Server window/log output. If you do not, then it’s likely that your firewall or Internet Service Provider is blocking incoming connections to TCP port 25. Before concluding this is the case, verify that the remote Telnet client can connect to other SMTP servers first (e.g. vert.synchro.net, TCP port 25). If it cannot, then this remote client probably has restrictions on which (if any) connections he can
