https://mailinabox.email/

Set up SSH key:
Create the ~/.ssh directory and authorized_keys

mkdir -p ~/.ssh && touch ~/.ssh/authorized_keys

Give the ~/.ssh directory and authorized_keys files appropriate file permissions:

chmod 700 ~/.ssh && chmod 600 ~/.ssh/authorized_keys

Open the authorized_keys file and paste the public key generated on PuttyGen:

Now set up to use the SSH key:

1, go to /etc/ssh
2, sudo vi sshd_config
3, edit the sshd_config file and configure it in this way:

Restart SSH:
service sshd restart

Remove email headers:

Create a file named header_checks /etc/postfix/header_checks and add the following:

/^Received:.*with ESMTPSA/              IGNORE
/^X-Originating-IP:/    IGNORE
/^X-Mailer:/            IGNORE
/^Mime-Version:/        IGNORE

Add these lines to /etc/postfix/main.cf:

mime_header_checks = regexp:/etc/postfix/header_checks
header_checks = regexp:/etc/postfix/header_checks

Rebuild the hash table and reload the postfix configuration:

postmap /etc/postfix/header_checks
postfix reload

Email logs:

To check the email logs you can run tail -f /var/log/mail.log to troubleshoot issues.

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