In my eventviewer I got a great amount of event ID errors 7010, MSEXchangeTransport. After reviewing the description I noticed all events came from the same IP-address. When looking up this IP, I found it to be a Unix/Linux host.
The full event ID is:
Event Type: Error
Event Source: MSExchangeTransport
Event Category: SMTP Protocol
Event ID: 7010
User: N/A
Computer: EXCHANGESERVER
Description:
This is an SMTP protocol log for virtual server ID 1, connection #1126. The client at “192.168.0.2” sent a “mail” command, and the SMTP server responded with “501 5.5.4 Invalid Address “. The full command sent was “mail FROM: “. This will probably cause the connection to fail.
For more information, click http://www.microsoft.com/contentredirect.asp.
What this Unix/Linux host does is sending the HELO command with the FQDN name of the mailserver. Except it also has a trailing dot (.). For example :
HELO domain.test.com.
When this is sent to an Exchange 2003 server it generates the following error:
501 5.5.4 Invalid Address
Solution
You are able to change Exchange and allow the trailing dot, but as this is not RFC compliant behaviour, I simply made sure the Unix/Linux host was configured to not send mail anymore.
If you want to change the behaviour of Exchange read the following knowledge base aricle : “501 5.5.4 Invalid Address” error message from a sending UNIX server
Hans Sleurink
Hans Sleurink works as a Consultant at Wortell in the Netherlands where he designs and deploys Unified Communications solutions. His main focus is on, but not limited to, Microsoft Teams (migrations), including Enterprise Voice, contact center solutions, AudioCodes, Direct Routing, Exchange, Office 365, Active Directory and other UC related topics.
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