Email: Difference between revisions

This is honestly an academic exercise because almost everyone uses Google's IMAP servers or other big ones, and anyone who doesn't are probably spammers. So, you have to try really, really hard and put a lot of settings up to not act like a spammer. A spammer can do these exact same things, too, which means you'll need to try really hard to gain reputation and manually remove yourself from blacklists until you've put in so much effort that people have to assume you <em>aren't</em> a spammer. <em>Then</em>, if you get compromised and a spammer gains access to your mail server, you have to go through all of this all over again!

** Name: <code>_dmarc.horatioexample.uscom</code>, Value: <code>v=DMARC1;p=quarantine;</code>

These DNS records are required to prevent spammers from spoofing your email. It's quite simple to spoof your email, simply set the "From" header to whatever you want, and so you could just use <code>From: steven@example.com</code> to a bunch of people. The <code>spf1</code> DNS record says that if an email sent outside of the IP <code>141.219.188.20</code>, then they'll assume someone else was trying to spoof your email. With no <code>spf1</code> record, there's no way to know if this email is spoofed or not, so your domain will not be trustworthy. If someone actually <em>does</em> try to use your email, it'll be quarantined following your <code>DMARC1</code> value. Finally, if someone spoofs your IP somehow, they will also require your private key to compare with your <code>DKIM1</code> public key shown in the third <code>TXT</code> record.

{{RootCmd|postfix stop}}

{{RootCmd|postconf maillog_file=&#x3d;/var/log/postfix.log}}

{{RootCmd|postfix start}}