Hi TechJoomla,
As everyone else who uses InviteX, I'm hoping some invitations will go viral. If they do ramp up, the number of emails could easily exceed the email send limits of a shared server. It would be much appreciated if you could incorporate the ability to use an external SMTP service. AcyMailing has this ability and is a good example.
If other readers of this forum agree, perhaps they could reply "+1".
Thanks for your consideration.