I recently came across a great tool for working with Encrypted email.
Thunderbird is a great free email client for OS X and Windows
Enigmail is a free plug-in for Thunderbird that allows for sending and receiving encrypted email messages. You can also sign emails.
https://enigmail.net/index.php/en/
Once downloaded and installed you need to also install GnuPG tools:
“The first and most popular option is to use the MacGPG package by
gpgtools.org. They provide pre-built binaries of GnuPG 2.0.22 and later for
users running OS X 10.6 (Snow Leopard) or later. Download the GPG-Suite
from https://gpgtools.org/gpgsuite.html and install it. If you don’t
want to use the other components (Certificate Manager, Apple-Mail plugin and
Services application), you can deselect them during the installation process.
Only the MacGPG component is required for Enigmail.”
Sharing your Public Key (don’t share Private)
https://enigmail.wiki/Key_Management#Share_your_public_key_manually
“Share your public key manually
On the Key Management window, select your key pair and click on File → Export Keys to File. Again, you will be asked whether you want to include your secret key in the saved OpenPGP key file: make sure you click on Export Public Keys Only this time. Save the ASC file, which will have a name like [email protected]_(0x89ABCDEF)_pub.asc.
This is a copy of your public key; notice the “pub” word at the end of the filename. You can now put the file on your website for people to download it, or carry it around in a USB drive to distribute it to people, or send it via email as an attachment.
Concerning this last option, there is a simple Enigmail shortcut for it: when writing your mail in the Message Composition window, simply click on Attach My Public Key or choose from the menu bar Enigmail → Attach My Public Key and Enigmail will attach it upon sending.”