Exchange 2010: Error 503 5.5.1 SMTP Bad sequence of commands (SMTP Error 503)
An interesting problem occurred with a customer today. The customer complained that no mails could be sent for some time. Mails were actually getting stuck in the outgoing queue. The Exchange 2010 server was supposed to send all outgoing mails to a relay server operated by the customer's provider. Not an unusual configuration so far. Answer ... Read more