Emails from haveibeenpwned.com silently blocked/not arriving in Outlook.com/Hotmail (worked in 2019, no rules or spam)

Question

Hi everyone,

Since around 2020 or so, emails from [no reply@haveibeenpwned.com] (legitimate Have I Been Pwned notifications/verifications) no longer arrive in my free Hotmail/Outlook.com inbox. They used to deliver normally back in 2019.

What I've already checked/confirmed:

• No custom mail rules set up to block or move them.
• Nothing in Junk/Spam folder.
• [no re ply @haveibeenpwned.com] and haveibeenpwned.com are not in Blocked senders/domains.
• Added haveibeenpwned.com to Safe senders and domains (but still no delivery).
• Tested by requesting a fresh notification via https://haveibeenpwned.com/NotifyMe → nothing arrives (not even bounced back).
• No visible errors or traces in my account.

This seems like a server-side silent rejection/drop by Microsoft (common with stricter filtering on bulk/security senders like HIBP via SendGrid). HIBP's FAQ states >99% of non-arrivals are due to the receiving server bouncing/rejecting them.

Has anyone else run into this with HIBP emails on Outlook.com/Hotmail recently? Did adding to safe senders eventually work, or did support whitelist it/fix a hidden suppression? Any other workarounds besides using a different email for notifications?

Thanks for any advice or similar experiences!

Answer 1

Hi Maikel,

You can submit a request to whitelist the domain here, just ensure that all the information needed is provided: https://olcsupport.office.com/

Answer 2

Microsoft could not solve this so I asked HIBP and they replied:

"According to SendGrid, you'd previously reported these messages as spam, so you ended up on a suppression list. I've just removed you from the list, give it another go now."

It works fine now, case can be closed! Thanks for your help.

Answer 3

Thank you, I just created a ticket at Microsoft.