I set my company exchange mailbox in 
Windows 8.1 mail. (outsite).
Everything works fine, but after i start the 
Windows 8.1 mail i get event with id 529 in the security log continously.
 Reason: Unknown user name or bad password
  Username: 
[email protected]
  range:
  Type of login: 8
  Logon Process: Advapi
  Authentication Package: Negotiate
  Workstation Name: SERVERNAME
  Caller User Name: SERVERNAME $
  Calling range BAR NUL
  Caller Logon ID: (0x0, 0x3E7)
  Caller Process ID: 4384
  Transmitted services: -
  Source Network Address: 56.43.213.122
  Source Port: 55 698   
If i close 
windows mail, events stop flooding the security log in the server.
Connection parameters in windwos 8:
email:
[email protected]
password
domain:company.local
username:myemail
server:mydomain.dyndns.org
SSL:yes.
Any idea whats the problem? I can check my mail, with the same setting on my android phone without any problem.
Thank you