Participants:

• Alice - sender (real Alice, or your bank, or social networks, etc..)
• Bob – recipient (for example you, or vice versa)
• Trudy – intruder of any kind (MitM, local infostealer, someone who has access to your laptop, internet or email provider, etc..)

In the case, if Alice sends Bob an email with its ID/bank statement/confirmation link... they (both) have some problems

Solutions review

Encryption

If you just wanna encrypt your email contents between two email addresses – you may just use a mailvelope.
It works easy and good for both sides:

• Just create your keys
• And share your public key to Bob
• Now he can use it for encryption when sends messages to your

Thunderbird could also resolve the issue, just read this note

There are a lot of clients, that support PGP encryption, just check the list here https://www.openpgp.org/software/

Backups

For some reason you may want to have yet another storage for your emails, for example: your laptops, Gmail, and Proton

Why? For cases, if your laptop is lost, your Gmail or Proton account will be blocked (or not accessible for maintenance) and you wanna find your letters anyway

Solution – email relays

I believe the best choice for today is https://simplelogin.io/, that is why:

• solve the problem – generates a lot of email aliases, that will forward all emails to other your own inboxes
• additionally provides a PGP encryption for all incoming emails, it's useful for cases if you want to encrypt messages from social networks or from your banks, but they do not support it

For paranoic: you may deploy it on your own hosting...

Email address protection

And again email relays:

• SimpleLogin (and others) also provides email aliases, that could be used as reverse email addresses (you may use this alias even for communications and your real email address will be still hidden)

Other services like this one: addy.io or relay.firefox.com (no PGP, as I remember)

Retention period

Ok, you are responsible for your mailbox, but sometimes you send something to the other side and you want to be sure, that its mailbox will not be the reason for your data leak

How is it today?

• A lot of users use Gmail – there is a protection of messages with confidential mode
  • your message will be removed after N days
  • additionally, you may request authorization by code from SMS (you should enter the phone number of the recipient, that you know)
• The same functionality from other providers, like protonmail or tutanota
  • but there you may define the password, for access to the email
  • they additionally may request email confirmation (to confirm the inbox owning)
  • and provide a replying possibility – right from the web page, the recipient reads the letter

Sender validation

By the way:

• if you use a PGP encryption you already have a sender validation (only if somebody does not own a sender's private key and its passphrase)
• also you may use PGP just for signature
• email relays provide you unique email addresses for each website, which is why if you receive an email not from your relay – you will be triggered by this red flag

Email as a chat

What about messengers?
A lot of them keep data as plain text (that is why the search function does not work offline 😉)

You may use your mailbox with backups, address protection, encryption, expiration periods, and sender validation like chat!

Just try Delta Chat

Top-level review

I described the easiest ways for a lot of people how to protect emails (addresses and contents), I hope someone can add more info (or concerns/questions) in the comments, and the post will be updated

Look at this checklist https://digital-defense.io/checklist/email/ , It believe it will be useful for someone