If they offer IMAP, they would also need to decrypt your data on their side, which I'm happy they go to lenghts to avoid. This is a case of Proton sacrificing

If they offer IMAP, they would also need to decrypt your data on their side, which I'm happy they go to lenghts to avoid. This is a case of Proton sacrificing convenience for privacy. If the former is more important for you than the latter, there are better alternatives out there.