Synchronet v3.17b-Win32 (install) has been released (Jan-2019).

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Relay Incoming SMTP Mail through Vertrauen

Your ISP restricts or blocks inbound connections to TCP port 25 so you are unable to have the Synchronet Mail Server receive email messages from public mail (SMTP) servers (which by standard convention always attempt delivery on TCP port 25).

Have another Mail Server (listening on TCP port 25) receive mail for your host on your behalf and then forward that mail to your Synchronet Mail Server (on TCP port 587), thus providing the service of a Mail Exchange (MX). Vertrauen can provide this Mail Exchange service for your BBS (yes, for free).


  1. Insure your Synchronet Mail Server is configured to accept SMTP mail submissions on port 587 (this is a default configuration, so it should already)
  2. Email digital man and ask for mail exchange services while providing the hostname of your BBS
  3. Once you get confirmation from digital man, you need to setup an DNS MX record for your hostname. If you are not using the dynamic name service, then you'll need to contact your domain name registrar to add the MX record. Otherwise (you are using, add “ -mx” to the end of your DYNDNS timed event command-line in SCFG->External Programs->Timed Events.

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