Q2750060: When I try to send an e-mail, I get ERROR 169: 'EncryptMessage failure in SSPI module'. What's wrong?
This is a bug in the Operating System's SSPI (Security Support Provider Interface) module. It happens sometimes to Microsoft Vista/7 x64 Operating Systems and Windows 2008 x64 Operating Systems. To solve the issue, apply the latest Service Packs and Hotfixes. For details, please check support.microsoft.com/kb/978918/EN-US.