Ah, I don't really care about telemetry, but their amazing outlook.com SMTP service rejects mail from small senders, and there's no way to successfully appeal.
Yeey, brave new megacorp world!
Yeey, brave new megacorp world!
Hello,
My name is [Kumar/Numan/Punith/Suresh/Sachin] and I work with the
Outlook.com Sender Support Team.
I do not see anything offhand for the IP (xx.xx.xx.xx) that would
be preventing your mail from reaching our customers.
Good bye and fuck off.
550 5.7.1 Unfortunately, messages from [xx.xx.xx.xx] weren't sent.
Please contact your Internet service provider since part of their
network is on our block list (S3150).
- is the exact same message being sent to many users?
- does it look like previous spam?
- are messages from this host being reported as spam by users?
We have plenty of techniques to filter out spam (those above and technical ones like DKIM to enable host reputation systems) and they mostly work great. What Google/Microsoft are doing is just monopolistic attitude and has nothing to do with spam filtering. Spam from big email servers is still common, but legit emails from smaller servers will not reach intended recipients, and will not produce any indication of that on either side of the communication. It's just silently going in the trash.
If there was at least a decent way to get allowlisted on their side, we could give them the benefit of the doubt and accept that email ecosystem has turned to an opt-in federation model. But the way they do it and prevent recourse is a clear abuse of dominant position to crush the competition.
Before I moved to fastmail, my email was consistently getting nullrouted by microsoft. Everything was setup correctly (SPF, DKIM, DMARC, ARC, etc...), and every other mail host I tried would receive my mail correctly. I send out a very low amount of email (3-4 per month?).
We (small devshop + some hosting + self-hosted email) hosted a few things for a foundation for years, and about two years ago they migrated the mail stuff to MS. (We continue to host a few sites, domains, DNS.) Now when they need something and send us an email we can't reply, because our IP is "listed".
Okay, I know spam can be bad, and fine-tuning spam filters is a PITA, so let's go through the delisting process, surely with enough perseverance eventually MS will tolerate us into their graces.
Well, it has been more than a year now, and still no luck.
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We have completed reviewing the IP(s) you submitted. The following table contains the results of our investigation.
Not qualified for mitigation x.x.x.x Our investigation has determined that the above IP(s) do not qualify for mitigation.
...
¯\_(ツ)_/¯