Some scientists are working on CPUs that can process encrypted data, but until they are successful in applying their theories and manufacturers can make what they design, all data must be processed unencrypted. This is at least partly why end-to-end encryption is considered necessary by some people as it substantially mitigates these kinds of issues. At the very least, the data in RAM must be decrypted, and if data on the storage drive is encrypted, then its decryption key must be somehow used to unlock the data so it can be used in RAM, which becomes problematic.
I really can’t recommend an ISP, as I have no basis for comparison. If the only goal is to get away from Google, et al, so they don’t have this bit of your information, you could simply look at alternative email ISPs, such as Rackspace, Lavabit, Protonmail, Runbox, etc. The only real advantage of MaIB may more storage, email addresses, etc.