Given the ambiguity of the errors in the maileater_nxd.log, the problem is most likely with the POP3/IMAP server that the SDM Server trying to connect and that the connection is being rejected.
It is important to keep in mind:
- SDM is making a connection to the given mail server based on the settings in the mailbox configuration and is acting as a simple mail client. There is nothing else that SDM is trying to do here. If there is no TLS or certificate in play, then the connection should not be hindered by any local security settings.
- The test to access the mail server via a web client such as Outlook is not a valid comparison test. This is because the web client could leverage other protocols besides POP3 or IMAP to connect to the mail server that SDM is experiencing problems accessing.
- One simple way to test access to the mailserver is to use a telnet command. In this example, there is a "mailserver" server that is running POP3 mail services on port 110. To test, run this command from an admin command prompt.
telnet mailserver 110
If POP3 services are active and available, one should get a message response such as this:
In an instance where there was a problem with the mail server, the above command did not return any message, the command simply hung and the connection was terminated after a moment of waiting.
In further testing, if one tries to use telnet on an active port that does not support such a connection, such as port 1443 which SQL Server uses by default, ie:
telnet mailserver 1443
The telnet command will also hang and terminates after some time of waiting.