Well, we started moving websites from a network server/local system hosting into their own locked down user account. The way it should have been in the beginning. We ran into a problem where sites that were using the CDO.Message com object couldn't send e-mails. They were getting an error saying that SendUsing configuration error. This one:
Issue: Number=-2147220502(0x800403EA) App [1002]
Source=CDO.Message.1
Description= -2147220960[0x80040220] The "SendUsing" configuration value is invalid
W