Comments on 2019-03-31 Email Server, Again

Day 1: Change the DNS records. This is what I added:

@ 10800 IN MX 10 mail.alexschroeder.ch
@ 10800 IN TXT "v=spf1 mx -all"
mail 10800 IN A 178.209.50.237
mail 10800 IN AAAA 2a02:418:6a04:178:209:50:237:1

Next step: reverse DNS. I wasted precious time trying to figure out how to do that until I discovered that I had to send a mail to the hosting provider of my server, apparently. Oh well.

Slowly things are coming back to me. Kallobombus Mail, for example. Or 2015-08-03 Switching to Postfix. And Raspberry Pi als privater Email Server. Uuuugh!

– Alex Schroeder 2019-03-31 11:49 UTC


Day 2: OK, so the hosting company says that the domain name service company should do it (Gandi). I don’t see anything in the menus but it seems to me that it should involve the PTR record type from what I can read. But apparently I cannot type it into the same file I mentioned above. This appears to be an error:

237.50.209.178.in-addr.arpa. 10800 IN PTR mail.alexschroeder.ch.
1.0.0.0.7.3.2.0.0.5.0.0.9.0.2.0.8.7.1.0.4.0.a.6.8.1.4.0.2.0.a.2.ip6.arpa. IN PTR mail.alexschroeder.ch.

Where does this stuff go? Somewhere on Gandi?

Apparently something is already configured somehwere, somehow: host 178.209.50.237 gives me 237.50.209.178.in-addr.arpa domain name pointer mx8.virtnode.com. but host 2a02:418:6a04:178:209:50:237:1 gives me Host 1.0.0.0.7.3.2.0.0.5.0.0.9.0.2.0.8.7.1.0.4.0.a.6.8.1.4.0.2.0.a.2.ip6.arpa not found: 3(NXDOMAIN) – whatever that means.

And where do I do this? Some sort of new “zone” file – on the Gandi site I see no way to do it, and on my own server I don’t think I have a name server installed. Should I?

– Alex Schroeder 2019-04-04 21:28 UTC


It sounds like your hosting provider is confused - maybe they think you’re just talking about regular DNS vs reverse DNS?

– Anonymous 2019-04-05 01:07 UTC


Yeah, I got the same advice on Mastodon (@fitheach, @freakazoid, @Frotz, all of them very helpful) suggesting the same thing. I sent them another message.

– Alex Schroeder 2019-04-05 08:20 UTC


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