How to Use Airmail with a VPN or Corporate Network

Problem

Airmail is not connecting or syncing emails while on a corporate network or VPN.

Common Issues

• Blocked Ports — Corporate firewalls may block IMAP (993), SMTP (465/587), or POP3 (995) ports
• VPN Routing — Some VPNs don't route email traffic correctly
• Certificate Errors — Corporate proxy servers may intercept SSL connections, causing certificate warnings

Solutions

Check Port Access

1. Verify with your IT department that IMAP/SMTP ports are open
2. Standard ports: IMAP: 993 (SSL), SMTP: 465 (SSL) or 587 (TLS), POP3: 995 (SSL)

VPN Configuration

1. Try split-tunnel VPN if available — this routes email traffic outside the VPN
2. If using full-tunnel VPN, ensure your email server's IP is whitelisted
3. Test by disconnecting VPN temporarily to confirm the issue is VPN-related

Certificate Issues

1. If your company uses a proxy that intercepts SSL, you may need to install the corporate root certificate
2. Go to Keychain Access and add the certificate to System Keychain
3. Mark it as "Always Trust"

Alternative: Use App-Specific Password

Some corporate setups require app-specific passwords instead of your regular password. Check with your IT department for OAuth or app-specific password requirements.