What is the best way to encrypt emails? I use gmail right now. Should I use a different provider or just some kind of software?
Thank you
GPG with highest strength AES encryption you can get.
There are better ways, using better encryption algoritms that provide better anti-tampering, but those are not available in an out-of-the-box software solution.
If you encrypt your mails, you can still use gmail, because noone - not even google - will be able to read them. Problem with gmail is that it's not privacy aware at all. Google itself uses the content of your emails - as far as it can read it - to profile you and build a bubble around you, basically, to brainwash you and deprive you of objective information. Most online mail services, paid or free, do that. Some don't, they don't use your email to sell your data or profile you. However, your mails, unless encrypted, will still be stored and analysed by secretive organisations.
If however you still use Windows or another non-FOSS operating system, don't even bother using encryption, first of all you can't be sure that what you see on your screen is actually want you want to see, even if the provenance is checked with a CA key, because Windows "manages" your CA keys for you behind your back and you can't change or delete any, secondly, all your key presses are obviously keylogged all the time (so good luck entering your encryption passphrase lol), because there is no other reason why Windows would need tens of megabytes of keyboard driver if it were just a keyboard driver, and thirdly, not only users don't know what the computer really does when running the closed source Windows system, but even Microsoft doesn't know, they have "inherited" Windows from IBM, and IBM has been building NSA backdoors into it's software since the 80's, they had it in Lotus Notes, they had it in OS/2, and they didn't tell Microsoft about it, and Microsoft didn't even bother to check the code, and when the infamous "third key" was discovered in Windows NT through logical analysis of CPU activity in the late 90's, Microsoft didn't have a clue what was going on, but they didn't change a thing, Windows 8 is also known as Windows NT 6.2, it's still the same rebranded IBM OS/2 software from the early 90's, and logical analysis of CPU activity is now impossible because the instructions are encrypted in the CPU itself, so instead of solving the problem, they just hid it deeper.