Gmail (thus Nanog) rejecting ipv6 email

Wed Apr 6 02:27:36 UTC 2022

On Tue, 5 Apr 2022, Owen DeLong via NANOG wrote:

>> Of course there's an argument that say "mom and pop should not run 
>> their own mailserver, there are professionals for that!" but at the end 
>> of the day what this really serves is deliberate and pre-mediated 
>> centralisation, slowly but steadily stamping out small players.
>
> As pop running his own mail server, I don’t buy that first argument at 
> all. However, I will say that if you are going to run an MTA on the 
> greater internet, then you have inherently as part of the social 
> contract, accepted the obligation to run it in accordance with the 
> current form of BCP and the further obligation to keep up with the 
> current definition of current BCP.

Let's talk about professionals?  Even assuming these grep's aren't 
perfect:

Number of gmail from/to messages in our last logs: 
# bzgrep gmail /var/log/maillog* | grep google.com | wc -l
1514

Number that gmail sent us that we flagged as spam and dropped at SMTP 
time:

# bzgrep gmail /var/log/maillog* | grep google.com | grep -i spamassassin 
| wc -l
641

Number that gmail users are sending, regularly, en-masse, to dead contacts
(mutually exclusive with above):

# bzgrep gmail /var/log/maillog* | grep google.com | grep -i "User unknown" | wc -l
785

Number of messages we've sent to gmail that have been rejected:
# bzgrep gmail /var/log/maillog* | grep google.com | grep -i 188131 | wc 
-l
9

Number of reported spams that have made it to actual abuse contacts at
google:
0

(they /dev/null abuse@, let me know how that jives with your BCP's.)

If you're sending them volumes, they offer you a feedback loop so they can 
report how spammy you look to them.  The inverse does not exist.  They 
have no documented SMTP error code that you can set that sigils to them 
that a user is spamming and should be rate-limited.

What gmail has here is a problem at scale.  There are large masses of 
people writing in bad english signing up for accounts and who will take 
payment to complete a captcha every single time if required, the same way 
every robocall you get will connect you with an actual human.

And gmail are, largely, "too big to block".

-Dan
Cranky Sysadmin

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