Le 01/09/2025 à 10:05, Niels Dettenbach a écrit :
Am Sonntag, 31. August 2025, 14:44:48 UTC+00:00:01 schrieb Antonin Verrier
via mailop:
I have a customer that has their email hosted by Gandi (French domain
registrar/hosting company) and can't send out emails because Gandi are
using a subset of Spamhaus' RBL (XBL/SBL it seems) to filter access to
mail submission (SMTPSA on port 465).
If (!) your customers is legitimate customer of Gandi which sends
authenticated email per their servers OR even their access network i would
see this as a misconfiguration by Gandi.
The customer is a legitimate customer of Gandi, who pay for Gandi's mail
hosting service.
They send mail via Gandi using SMTP/TLS on port 465, using Thunderbird
which is configured according to Gandi's documentation.
That has worked fine for a few month. And suddenly, when talking to
Gandi's SMTP server, Thunderbird throws an error message related to
Spamhaus listing.
Yes, at first I thought this was a misconfiguration on Gandi's side ...
but I checked their support website and it states that do check Spamhaus
RBL for mail submission.
BLs typically are used to help valuing spam probability for incoming - non
authenticated - email (even then: hard blocking a sender because the senders
IP is in a single BL leads to at least some false positives. Such service
would be not really suitable to run some reliable email server / services on
it).
Yes, I'm aware how RBL work and should be used. That's why I think what
Gandi is doing is weird...
Running a email server is "easy", but running a reliable email service
requires much more then that. I would let do that skilled specialists if you
rely on your email traffic. ß)
But i might wrong if i interprete your situation wrong...
cheers,
niels.
_______________________________________________
mailop mailing list
[email protected]
https://list.mailop.org/listinfo/mailop
