MICROSOFT is blocking lddb.com emails right now - SOLVED

admin · Posted: 02 Aug 2026, 11:14

If your email is:

@hotmail.___
@live.___
@outlook.___
@msn.___

they are not being delivered right now:

Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [163.172.105.186]
    weren't sent. Please contact your Internet service provider since part of
    their network is on our block list (S3150). You can also refer your
    provider to http://mail.live.com/mail/troubleshooting.aspx#errors.
    [Name=Protocol Filter Agent][AGT=PFA][MxId=11BDDBC77DA88B9F]
    [CY4PEPF0000E9D6.namprd05.prod.outlook.com 2026-08-02T10:09:59.297Z
    08DEEDE3C1B4537C]

My ISP is not being very helpful + Microsoft updated the website to get notified per IP (based on the reverse DNS) to per range (based on the whois).
So I can't register my specific IP for updates/notifications.

I'm trying to forward each email by hand but they are MANY of them coming all the time...

Julien

firehorse_44 · Posted: 02 Aug 2026, 11:36

Do you have an opinion as to why this is happening ?
What is to gain by Microsoft ?
Is this a control issue or a money issue ?
Curious !

admin · Posted: 02 Aug 2026, 11:40

firehorse_44 wrote:

Do you have an opinion as to why this is happening ?

I'm just a single IP in a sea of other servers next to mine.
If one goes rogue and starts spamming... the whole block gets banned.

I'm collateral damage...

Julien

admin · Posted: 06 Aug 2026, 07:45

My ISP engaged directly with Microsoft and the emails are going through normally again for the past ~3 hours.

That's a relief!

Julien

MICROSOFT is blocking lddb.com emails right now - SOLVED

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