Comment by kazinator | Hacker News Reader

Comment by kazinator | Hacker News Reader

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> So, starting today, the MX records of my personal domain no longer point to the IP of my personal server. They now point to one of the Big Email Providers.

A MX records don't have to point to an IP; it can point to a host name.

My MX record is a dynamic DNS host name.

> Big email servers permanently blacklist whole IP blocks and delete their emails without processing or without notice. Some of those blacklists are public, some are none.

OK, but if you're having trouble sending, that's no reason to do anything with your MX record, which is for receive only. Just route outbound SMTP through someone forwarding service.

I've run my mail domain for twelve years. In that time, I've not sent SMTP directly to anyone; always through the SMTP forwarding host run by my ISP.

Well, you know, the mail is going through that ISP anyway! If I could directly connect to port 25 of various hosts around the net, I would still be routing through that ISP's hardware. So the fact that mail is routed at a higher semantic level through their SMTP server, rather than just at the IP level, just almost just a footnote.

According to Hoyle, MX records must point to a domain name. The cannot contain addresses or point to aliases. Some mailers can tolerate IP address literals in MX records, but that is not universal and will cause problems.

Unless you're doing something special, there is a big difference between sending your mail to the recipient's smtp server and relaying it through you ISP's smtp server. The difference is that if you send it direct the ISP can't read it, because it's encrypted. If you relay it, the ISP can read your mail, and even tamper with it, unless the message itself has been encrypted with something like pgp.

Your ISP can log and analyze all SMTP traffic if they want to, whether it's being processed by their mail relays or not.

I believe most SMTP servers talk SSL/TLS, so, yes, sending mail directly to an SMTP server that doesn't belong to the ISP prevent the ISP from reading the mail.

Well sure, but if you're worried about traffic analysis you've got bigger problems. The difference here is that if you relay through your ISP they can read the contents of your messages. If you don't, they can't.

But this is the fault of the party you'd like to connect to; they are the ones refusing your direct SMTP connection because your IP address smells funny so that you have to resort to forwarding.

Maybe it's possible to work things out with particular such destinations. If there are certain parties to whom you'd like to send mail more securely, maybe they can give you an account on their SMTP server.

To everywhere else you go through your SMTP provider.

I think the author didn't want to say something technical about this and just wanted to say, that with changing his MX record, that his email server has changed.

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