Sorry Grant. Still couldn't replicate it, using:

exec xp_smtp_sendmail

@to = 'myusername@myisp.com',

@from = 'mccork',

@attachment = 'c:\boot.ini',

@server = 'mail.myisp.com',

@subject = 'subject subject subject'

Maybe you're right and the NT SP and SQL 7.0 SP do combine to cause problems.

There's a mention in the doco about previous problem with SQL 7.0 and opends60.dll, which is fixed now. My version of mssql7\binn\opends60.dll is dated Apr 9 2002. What about yours?