I'm getting a lot of Event 4625, which is a logon failure. The logon Subject user account on these failures is the my Exchange server. The target account is a Null SID with no name. The error says that the account is disabled.
I will post the entire error message below, but it seems odd that our server couldn't talk to itself. I am concerned about what is causing this and what side effects it may have.
Note that we are not experiencing any particular problem with our mail flow. I found this by accident while looking for something else.
An account failed to log on. Subject: Security ID: SYSTEM Account Name: EX-2013-SRV$ Account Domain: OURDOMAIN.COM Logon ID: 0x3E7 Logon Type: 3 Account For Which Logon Failed: Security ID: NULL SID Account Name: Account Domain: Failure Information: Failure Reason: Account currently disabled. Status: 0xC000006E Sub Status: 0xC0000072 Process Information: Caller Process ID: 0x1240 Caller Process Name: C:\Windows\System32\inetsrv\w3wp.exe Network Information: Workstation Name: EX-2013-SRV Source Network Address: - Source Port: - Detailed Authentication Information: Logon Process: Authz Authentication Package: Kerberos Transited Services: - Package Name (NTLM only): - Key Length: 0 This event is generated when a logon request fails. It is generated on the computer where access was attempted. The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe. The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network). The Process Information fields indicate which account and process on the system requested the logon. The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases. The authentication information fields provide detailed information about this specific logon request. - Transited services indicate which intermediate services have participated in this logon request. - Package name indicates which sub-protocol was used among the NTLM protocols.