My
2 cents into this email discussion.
Firstly, I don't know of ANY email service/server (SMTPD) forwarder and receiver that provides anonymity - as of this writing they cannot encrypt your email address

But, the servers can communicate using secured and encrypted protocols when configured with SSL/TLS.
Secondly, an email messages can be encrypted, but the encryption only works if a client on each end uses the same encryption/decryption mechanism
Thirdly, There are 3 major security schemes to route email messages:
1) S/MIME: Secure/Multipurpose Internet Mail Extensions based on a set of public and private keys and asynchronous encryption.
2) PGP: since 1990s, Pretty Good Privacy - user creates a pair of public and private keys) before they can send messages, or the secure message provider does that for the user.
3) Bitmessage: users must create a Bitmessage address (a pair of public and private keys) before they can send messages, or the secure message provider does that for the user.
End-to-end encryption improves delivery of your emails and stops spoofing of your communications.
SPF, DKIM, and DMARC are the most widely used techniques. SPF uses the IP addresses to send emails on behalf of a particular domain, allowing recipients to identify the sender. On the other hand, DKIM is a digital certificate that is attached to emails. It enables the recipient of an email to confirm that the content or headers of the email were not altered (faked) during transmission.
So, if you consider hosting you own email server get familiar with the topics as above

Or, just use any free email service if you don't give a damn about IT bullshit and how things work in the totally unsecured TCP/IP world.