Author Topic: PSA: If you did not receive a mail after registration - try again  (Read 130 times)

Peter

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We had a bit of a hiccup recently. Or rather, Gmail had it with us.
Just a week or so ago we have enabled full http/2 and IPv6 support on all our sites (forums, main, builds).
Everything went smooth, until today I received a mail from a kind user - telling me he did not receive the registration email.

I was baffled because the queue was empty - telling our mails did go out. So ... if they go out, where do they end up?
Sent a mail to "mail-tester.com", and again 9/10 score. Yay. But then no mails for users? Nay?

Started digging logs focusing and Gmail and there it was. Turns out if you have no ipv6:.. SPF record published, Gmail will eat your mail.
So I corrected our record and we are all good.
Thanks for your understanding and feel free to email me (my address is at the top of the forums) if something like this happens again.
- qBittorrent team - server and forum administrator.
- Hungarian translation reviewer/moderator (+ translator).

Peter

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Re: PSA: If you did not receive a mail after registration - try again
« Reply #1 on: October 22, 2017, 12:47:16 am »
Okay, Gmail had us again. So apparently, it will randomly eat your mails again, if it does not like your IPv6 PTR record.
We have a PTR record for our IPv6 address published - but Gmail does not like it ... sometimes.

Our messages went out like 90% of the time. But 10% got rejected. It's crazy, I know.
Same happened with the SPF record lacking ipv6. Google also ate those, but not all.
It's really fun to track issues when only random mails disappear.

Anyway, fix was to move Postfix to pure ipv4.
Here is the tutorial I used: https://support.plesk.com/hc/en-us/articles/213936285-Unable-to-send-an-email-Our-system-has-detected-that-this-message-does-not-meet-IPv6-sending-guidelines-regarding-PTR-records
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Switeck

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Re: PSA: If you did not receive a mail after registration - try again
« Reply #2 on: October 22, 2017, 01:32:56 am »
I am concerned that even if Gmail only rejects some IPv6 PTR records that the root cause of the rejection might be related to this:
Chilling effects on qBitTorrent...
https://qbforums.shiki.hu/index.php/topic,5165.0.html

And in particular:
https://www.reddit.com/r/torrents/comments/6obxsa/google_bans_bittorrent/

Officially, Google is doing this ("eating" emails) to block spam according to this:
https://support.google.com/mail/answer/81126?p=ipv6_authentication_error&rd=1#authentication

Peter

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Re: PSA: If you did not receive a mail after registration - try again
« Reply #3 on: October 22, 2017, 11:18:08 am »
Yeah the anti-virus situation is horrible. Not just for qBittorrent but the entire industry.
On today's market there are three kinds of anti-viruses:
- Ones that have good detection, performance but give you NO CHOICE. (Bitdefender, Kaspersky)
- Ones that have good detection, performance and give you the choice. (ESET)
- Ones that just suck and basically false flag everything. Because if everything is a virus, you can't get an infection, lol. (Comodo)
- Ones that just do nothing. (Microsoft Defender)

Those are just examples for each, there are many more products that fall into each 'socket'.

@Email filter: I read that article and we had SPF/DMARC and everything published and sorted out since we started sending emails.
The trouble was that we added IPv6 support. And postfix - for some ridiculous reason - defaults to "all protocols", meaning it will try to send out ipv6 first.
Again, would be no trouble. Microsoft, Yahoo, they accepted all our mails. Oh, and Gmail did too. Some, at least.
The issue is that it should reject all right off the bat, and not just eat some randomly. And yeah, Postfix should default to ipv4 as well.
(Wish I could set up IPv6 setting, but the PTR our provider gives us just not good enough for Google.)

@Google bans bittorrent:
I am surprised they did not go after "Ad Nauseam" ( https://adnauseam.io/ ) yet. :)
- qBittorrent team - server and forum administrator.
- Hungarian translation reviewer/moderator (+ translator).