Error starting antispam engine. [23]

[Pistol Pete]

Every time I open my Microsoft Outlook Email I get the same error message:
"Error starting antispam engine. [23]"
Does anybody know how to fix this?

FYI
I have enabled the Antispam Protection, the email client protection and the email client integration.

[estbird]

What OS?
What kind of user profile do you have (roaming, local, something special, ...)?