Due to a power issue last week, our SonicWALL NSA3500 with the enhanced OS got fried and we had to resort to an older model with the standard OS until the new unit arrives. The problem relates to setting up the older unit to be able to access our webmail from outside the organization. On the inside of the firewall we can use a browser to access https://webmail.domain.com/owa but this does not work outside the firewall. The one to one NAT is configured with the proper WAN and LAN addresses as per our MX record pointers. Is there an access rule that is required along with the NAT policy?