Can't believe in 2025 on "hacker news" people are still asking if Microsoft is the way to go. No, it isn't. It has never been.
OP is having problems sending emails to Microsoft 365, they don't use it themselves.
Ask HN: Is there hope for Microsoft 365 support?
41–50 of 60 posts
Re: Ask HN: Is there hope for Microsoft 365 support?
#42MS are notorious for blacklisting IP ranges from providers like Linode, which makes it impossible for a small biz to run its own commercial system. I'm not surprised they also keyword block, because Outlook flags Microsoft's own marketing messages as spam. There really needs to be some kind of global Digital Bill of Rights which provides legal recourse from these giant sclerotic algo-run oligopolies. MS, Meta, Amazon…
Yeah, this is kind of the point. I'm not sure there's even a legal process for this as this is entirely under MS (opaque) internal control and we're not even based on the US.
Never attribute to malice that which can be explained by stupidity.
We had the same thing happen with any email with 2f anywhere in the message body on Google workspace
The "2F" URL decodes to slash / and a third party registered our 2f.com (probably for nefarious purposes)
That kicked on the automatic filtering on messages that had URL encoded links and started blocking them.
Eventually, we had to register 2fgoogle.com ourselves to escalate the issue.
Re: Ask HN: Is there hope for Microsoft 365 support?
#43Earlier quoted context omitted.
Are you sure that it's MS who's blocking? Just think it's weird that they show it as delivered to recipient, sounds like they send the mail and something weird happens after.
With excessive spam scores, Microsoft silently ignores your email. Just swallows it up, reports it as delivered, but never actually does, not even in your spam folder. It's possible that this is a technical issue or a submission server issue, but it's not uncommon for Outlook to make email disappear.
This sounds like what's happening to us, but only if the dreaded 25friday.com keyword is included on the email content
Re: Ask HN: Is there hope for Microsoft 365 support?
#44Earlier quoted context omitted.
Yeah, this is kind of the point. I'm not sure there's even a legal process for this as this is entirely under MS (opaque) internal control and we're not even based on the US.
Never attribute to malice that which can be explained by stupidity. We had the same thing happen with any email with 2f anywhere in the message body on Google workspace The "2F" URL decodes to slash / and a third party registered our 2f .com (probably for nefarious purposes) That kicked on the automatic filtering on messages that had URL encoded links and started blocking them. Eventually, we had to register 2fgoogle…
Ok, that was smart. I bet it was fixed quickly.
Re: Ask HN: Is there hope for Microsoft 365 support?
#45It seems likely your site had something detected as malware, or is still being detected as malware.
When I test sending a mail to my M365 account with your URL mentioned I find that it gets quarantined (same as if I try to send an email from my M365 account with that URL).
In your M365 test tenant, you should be able to go https://security.microsoft.com/quarantine and see that the emails are getting quarantined, with this information provided as to why:
Detection technologies: URL detonation reputation, Mixed analysis detection
Given that it says "URL detonation reputation" rather than just "URL detonation", that suggests it's using historical information rather than having performed a new test.
This is Microsoft Safe Links functionality - at the very least since you should be able to find the quarantined emails, the headers will contain a correlation ID support can use, although they might not have much power over safe links.
Re: Ask HN: Is there hope for Microsoft 365 support?
#46It seems likely your site had something detected as malware, or is still being detected as malware. When I test sending a mail to my M365 account with your URL mentioned I find that it gets quarantined (same as if I try to send an email from my M365 account with that URL). In your M365 test tenant, you should be able to go https://security.microsoft.com/quarantine and see that the emails are getting quarantined, with…
Thank you, you've gotten further than I have.
On my "quarantine" I can't find anything (it's empty) therefore I can't also check what's going on. But "URL detonation reputation" is consistent with the behavior we're observing.
Re: Ask HN: Is there hope for Microsoft 365 support?
#47Re: Ask HN: Is there hope for Microsoft 365 support?
#48It seems likely your site had something detected as malware, or is still being detected as malware. When I test sending a mail to my M365 account with your URL mentioned I find that it gets quarantined (same as if I try to send an email from my M365 account with that URL). In your M365 test tenant, you should be able to go https://security.microsoft.com/quarantine and see that the emails are getting quarantined, with…
Thank you, you've gotten further than I have. On my "quarantine" I can't find anything (it's empty) therefore I can't also check what's going on. But "URL detonation reputation" is consistent with the behavior we're observing.
Edit: Nevermind, I see that you've already done this.
It might be worth it to pony up for an M365 license or two, send yourself an email, and then open a support ticket inquiring why the email was blocked. I would even avoid mentioning that you are the sender. Just pretend you're a regular customer who receives email from your domain and you're wondering why it was blocked and if there's anything that can be done to stop it from happening.
Re: Ask HN: Is there hope for Microsoft 365 support?
#49MS are notorious for blacklisting IP ranges from providers like Linode, which makes it impossible for a small biz to run its own commercial system. I'm not surprised they also keyword block, because Outlook flags Microsoft's own marketing messages as spam. There really needs to be some kind of global Digital Bill of Rights which provides legal recourse from these giant sclerotic algo-run oligopolies. MS, Meta, Amazon…
Which cloud server providers are safe from sporadic Microsoft IP blacklisting?
Re: Ask HN: Is there hope for Microsoft 365 support?
#50You have Unified Support and dedicated CSAM assigned to your case? If you're trying to solve this over Basic support...Good luck friend!
What does that acronym mean? I'm not sure if you made a typo or if it's very unfortunate naming.
IIRC Microsoft somewhat recently changed the positions name to Customer Service Account Manager. Absolutely wild nobody on the inside spoke up about this one, but with how awful Microsoft is at naming things generally I could see anyone who knew deciding to just watch it play out.