In Exchange 2003, Public Folders are not receiving internet emails, but they can receive internal emails!
What I have done so far:
1- Folders are mail enabled
2- Anonymous Permission as a Contributor
3-Under the properties of the folder the "Delivery Restrictions" is grayed-out because still under mixed mode.
Basically everything looks fine to me my little knowledge!
I'm not sure if this article is related:
Thank you in advance.