I am having a similar issue. I regularly send email to Evernote notebooks. But for some reason, now only some emails are correctly sent to the Notebook designated in the Subject Line (@notebook name). Others go to my default notebook. I'm a premium user. This has not been a problem before, and now it is a persistent issue. I use Spaces, and I had a tech tell that the email function won't work for notebooks in Spaces, but it was working fine before last week. Frustrating and I may have to use a different service as I cannot afford to send and reorganize every day.