IIS SMTP Configuration - Unspecified Error

I encountered an strange error when I was working on I was on incoming email setting in MOSS; while configuring IIS SMTP I got error message : Unspecified Error. Searched on the box and found that the last hotfix  946517 that i installed was to fix the issue related to IIS

SMTP Configuration - Unspecified Error

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This  issue is fixed by the hotfix mentioned in https://support.microsoft.com/default.aspx/KB/950426