I use WG as a Firewall and an SMTP Proxy running on my Public IP. (Firewall has a hole for SMTP. SMTP Proxy bound to Inet only. WG SMTP server is disabled.) Proxy forwards all mail to localhost on port 2525 which is where MS IIS Virtual SMTP Server accepts mail and is scanned by GFI Mail Essentials (which only runs on MS IIS SMTP w/Exchange 5.5). MS IIS SMTP relays internal domains to Exchange 5.5 where mail is delivered to Outlook clients. I have disabled 8bitmime on the IIS SMTP.
I'm having trouble with some emails logging in the WG History (under Activity) as "SMTP: " only (no header data following "SMTP: "). Normally a message will log as "SMTP: inbound message from <source address> to <internal address>" We're getting word that these emails are being NDRed to senders with "550 request denied" errors. I'm not requiring authentication. My Relay protection is through other means (local domains only, etc.).
What would cause WG to strip certain messages and NDR them but not others. I'm not seeing any patterns or obvious config problems.
Thanks...
Pete Hustvedt
pete@hustvedt.com