Exchange 2003 sitting on a Server 2003 using VMWare. Sonicwall TZ190 for firewall. Symantec MailSecurity for Exchange ver 18.104.22.1685
Through last night server was receiving emails from external sources. Discovered a problem because was using a smarthost and they stopped sending emails. Have them off the smarthost and able to send emails to external sources w/o issues. Appear to have no issues receiving emails internally.
Checked everything can and everything looks fine, MXToolbox showing proper MX record. Can telnet (via both IP and DNS values) and get initial response from server from outside location. Can send email outside but when try to reply it does not show in Outlook (no users reporting any email inbound since yesterday). If send an email (not a reply) same - no email receipt.
Verified everything looks ok in Virtual SMTP settings. IPAddress is correct. While close have not hit database limit (approx 60Gb and yes have the 75Gb switch in place).
Spent a ton of time reviewing the Sonicwall but those settings look ok. Tried calling Sonicwall support and unit EOL was July of last year and refuse to assist even if offer to pay. Reset both the internet (DSL) and Sonicwall - no change. Rebooted the Exchange server - no change.
Is a medical equipment repair firm so very important that their inbound is restored.