Message Digest emails not properly translated

I have a site setup with: Message Digest, Message Subscribe, Message Subscribe Email Frequency. I have enabled subscribe_og and email_og and I've written my custom module to create the messages as described on https://drupal.org/node/2180229. All works fine so far.

I have a second language enabled, translated my Message type, and translated my content. If I create a new user and change their language to the second language, they get other emails translated fine, but the Message Digest email is not translated at all.

I'm not sure it matters, but I'm also using entity_translation configured with field translation for my content.