Tag: Troubleshooting 501 5.7.1
How to Troubleshoot 501 5.7.1 Errors with Exchange
If you’ve ever had “501 5.7.1 This system is not configured to relay mail from…” errors when relaying email through Exchange, it means that your email client did not properly log on to the mail server because it failed the SMTP authentication check. (Jan 31, 2011)





