This is much more important than what you think. The US Government’s position is that an email is like a post card, there is ZERO expectation of privacy.

ZERO.

The same way you can’t keep your postman from reading your post cards, you just can’t keep your email from being read as it bounces from server to server on its way to be delivered.

By the way, there’s no such thing as infallible encryption. The only thing you can do is make it as hard (hard is defined as expensive) as possible for somebody to break into one of your encrypted emails or files. You can use easily available software, like Pretty Good Privacy (PGP) or its free/open source equivalent, GPG, to protect your communications good enough so it is literally impossible for anyone to try to crack them by brute force.

That is, unless that “anyone” is a nation state with very deep pockets, and you happen to be of interest to them. Remember when I said it isn’t infallible? In order to break something like PGP, you don’t have to break the message itself, all that you need to do is be careless about protecting your private key, and/or using a weak pass phrase for the private key.

Either of these things will make it easier for an individual or company to be able to brute force into your protected communications.