smtp is not the internet connection so no. Also not including their DNS, but that seems to have been fine recently, although a working DNS is a requirement for most users as the ones in routers is just a simple redirect.
xtra and slingshot have been rock solid connections IME other than chorus outages, flatmates xnet, sisters LLU orcon, mums xnet etc - much less so.
speeds on the orcon LLU and the xtra are among the best - and the only one that is reliable and fast is the xtra one. At $2 a gig for the excess its getting into the realm of being affordable for high users as well.