So, seems like Microsoft's *.olc.protection.outlook.com mail servers are currently using certificates signed by an distrusted root CA[1].
That seems like a shocking level of incompetence.
It means that any mail server supporting MTA-STS is currently unable to deliver any mail to them.
[1] DigiCert Global Root CA which has been scheduled for distrusting since 2023 https://knowledge.digicert.com/general-information/digicert-root-and-intermediate-ca-certificate-updates-2023
Thomas Pike
npub1zn…2m9nr
2026-06-19 22:41:27 UTC
Author Public Key
npub1znwwdkgquxle27fdqq2z7hrwe06c92l4m2j54qu78jmxh0rrxfusc2m9nrSeen on
wss://relay.momostr.pinkPublished at
2026-06-19 22:41:27 UTCEvent JSON
{
"id": "8637b9f4dc40f695219504b32a9af476f8b83ba09cf7b4ea0a6b4ea4395659d4",
"pubkey": "14dce6d900e1bf95792d00142f5c6ecbf582abf5daa54a839e3cb66bbc633279",
"created_at": 1781908887,
"kind": 1,
"tags": [
[
"proxy",
"https://social.vivaldi.net/@thomasp/116779180878021816",
"web"
],
[
"proxy",
"https://social.vivaldi.net/users/thomasp/statuses/116779180878021816",
"activitypub"
],
[
"L",
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],
[
"l",
"pink.momostr.activitypub:https://social.vivaldi.net/users/thomasp/statuses/116779180878021816",
"pink.momostr"
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[
"-"
]
],
"content": "So, seems like Microsoft's *.olc.protection.outlook.com mail servers are currently using certificates signed by an distrusted root CA[1].\n\nThat seems like a shocking level of incompetence.\n\nIt means that any mail server supporting MTA-STS is currently unable to deliver any mail to them.\n\n[1] DigiCert Global Root CA which has been scheduled for distrusting since 2023 https://knowledge.digicert.com/general-information/digicert-root-and-intermediate-ca-certificate-updates-2023",
"sig": "d48e6610863683465185f8df248b4b17e0b2bfb94465ca9e15fd9c29f5e611df7724f99a79ba50d04ae4de84cd817c1b896ed052e0231a8e8676654d7fbee8b2"
}