On a system running XP and Office 2002, "Microsoft Update" downloaded and
installed the Office SP3 update. Everything had been working fine up until
this point.

Now when I try sending an email, I get this message:

Microsoft Outlook could not sign or encrypt this message because you have no
certificates which can be used to send from the email address

Do I really need a certificate? If not, how to I disable this?

If I do need a certificate, how do I get it?

Thanks,

Tony