NS delegation works for exactly one provider.
Ahem, that's one provider per subdomain. Why do you think that Orbitz
sends their newsletters from email.orbitz.com?
And I don't see how CNAME's would work
I agree, they're only useful for planting an alias if some leaf's name
changes.
R's,
John
_______________________________________________
NOTE WELL: This list operates according to
http://mipassoc.org/dkim/ietf-list-rules.html