Currently we have SharePoint 2007 and we have Exchange Server 2007. Within our company SharePoint is able to email people alerts and items from work flows. Recently we have opened up one of our SharePoint Applications to our partners, though when they try and set up for alerts or when our work flows try to send information to them they never receive it.
For example our SharePoint can email <username>@ourDomain.com, but it cannot email <username>@gmail.com.
Any advice will be greatly appreciated.