A client of mine have a problem with EPiServer mail 4.4 on Episerver CMS 5 R2 SP2 on their production machine. Whenever the client tries to send a newsletter through EPiServer mail using their custom made recipient list (basically the same example solution found on EPiServers site) they get an error message in red text in the editor saying "Specified cast is not valid". The error just recently appeared and it has been working perfectly many times before that. When searching for the error message all issues are pointing towards some sort of conversion error in the database but the database looks fine. Also if we manage the recipients as a normal recipient list everything works fine. Anyone have any idea what the problem can be?
Also does anyone know if it is possible to test/simulate a sendout of the custom recipient list on EPiServer Mail without actually sending to all of the recipients? Perhaps there is a test account we can use or something like that?