POPcon Support
Email and phone support is included with all our products. We respond quickly.
Contact: support@servolutions.com
Exchange Server Configuration Guides
- Configuration of Exchange 2013 or 2016 Server
- Configuration of Exchange 2010 Server (incl. SBS 2011)
- Configuration of Exchange 2007 Server (incl. SBS 2008)
- Configuration of Exchange 2003 Server
- Configuration of Exchange 2000 Server
- Configuration of Exchange Server 5.5
Frequently Asked Questions
The Knowledge Base covers 60+ FAQ articles. Frequently referenced topics:
Configuration & Authentication
- Transfer POPcon settings to a new server
- Gmail with OAuth2 (modern authentication)
- Microsoft 365 / Outlook online with OAuth2
- Why POPcon needs the “accepted domains” setting
- ISA-Server proxy configuration
Email Delivery Issues
- “530 5.7.1 Client was not authenticated” from Exchange
- “550 5.7.1 Unable to relay” from Exchange
- Exchange does not accept emails larger than 10 MB
- Emails to unknown recipients stuck in queue
- BCC recipients do not receive the email
- Distribution group rejects external emails
- IONOS blocks non-delivery reports and out-of-office messages
Error Resolution
- “452 4.3.1 Insufficient system resources”
- “451 4.7.0 Temporary server error” (Exchange 2013)
- “421 4.4.1 Connection timed out”
- Connection unexpectedly closed
- STARTTLS command error
- Port 25 blocked / cannot reach Exchange
Advanced Topics
- How the antispam feature works
- Wildcards in the anti-spam blacklist (`*@spammer.com`)
- Spam checking is very slow
- Mail does not reach mail-enabled public folders
- Enable non-delivery reports (NDRs) in Exchange 2003
- Virus scanner deletes .msg files — POPcon hangs
- Trigger mail retrieval from command line
- Where is the POPcon log file?