After nearly 2 years I decided to close this project down. The major reason is our big friend Nintendo. Had contact with a lot of users over the post 2 years and the main problem was emails not arriving or images attached to emails not arriving. The Nintendo mail servers are in my opinion to strict with handing emails to run a service like mail2wii against it. Then again I don't blame Nintendo for doing so since no one wants spam and the Wii is a very bad place to have certain kinds of spam ;). All these little problems I couldn't resolve turned the project into a drag.
Anyway I hope everyone that used the service was happy with it. The processing scripts will run until the domain expires and will be stopped afterwards.