Outlook is returning Remote Server returned '421 4.3.2 Service not available' for two of my groups.outlook.com groups

Anonymous
2022-06-28T02:36:22+00:00

* * * Mod note: See the post by Diane Poremsky MVP * * *

Yesterday and today outlook.com is refusing all group email.
I have two different groups that I use weekly. Today I get this message.'

The recipient's email system isn't accepting messages now. Please try resending your message later or contact the recipient directly.

Generating server: BN6PR19MB0962.namprd19.prod.outlook.com
Total retry attempts: 4

___@___.___
Remote Server returned '421 4.3.2 Service not available'

Original message headers:

Received: from SA0PR19MB4412.namprd19.prod.outlook.com (2603:10b6:806:ba::17)
by BN6PR19MB0962.namprd19.prod.outlook.com (2603:10b6:404:74::9) with
Microsoft SMTP Server (version=TLS1_2,
cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5373.18; Sun, 26 Jun
2022 19:00:06 +0000
Received: from DM4PR19MB6342.namprd19.prod.outlook.com (2603:10b6:8:a7::11) by
SA0PR19MB4412.namprd19.prod.outlook.com (2603:10b6:806:ba::17) with Microsoft
SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id
15.20.5373.18; Sun, 26 Jun 2022 18:59:37 +0000
Received: from DM4PR19MB6342.namprd19.prod.outlook.com

WHAT IS GOING ON WITH OUTLOOK GROUPS??

I create a NEW group to test and it ALSO returns the same error.

* Pinned until August 1, 2022.

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  1. Anonymous
    2022-07-05T11:35:00+00:00

    Can we please have an update on this issue - silence is unacceptable

    This might have something to do with it -

    https://arstechnica.com/information-technology/2022/06/microsoft-exchange-servers-worldwide-hit-by-stealthy-new-backdoor/

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  2. Anonymous
    2022-07-05T12:08:48+00:00

    It's extremely frustrating and the lack of effective communication is very poor customer service. I came across the article below, which might possibly point to the source of the problem. It also says that it is complex to rectify. On the one hand I can understand that Microsoft would not want to broadcast that their servers had been attacked and they have a problem; on the other hand, they need to be a bit more informative - just repeating that engineers are working on it doesn't cut the mustard. I'm going to try something tonight to see if it will act as a work-around, although it my be laborious. If it does, I'll let you know.

    Microsoft Exchange servers worldwide hit by stealthy new backdoor - Ars Technica<br><br>Ars TechnicaResearchers have identified stealthy new malware that threat actors have been using for the past 15 months to backdoor Microsoft Exchange servers ...

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  3. Anonymous
    2022-07-05T12:18:00+00:00

    What do you have to loose at this point? Keep us informed. Thanks.

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  4. Anonymous
    2022-07-05T13:15:16+00:00

    No response or update to the case I opened. Microsoft has been too quiet on this subject.

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  5. Anonymous
    2022-07-05T13:35:08+00:00

    Very poor customer service. All I've had over the past two weeks is three idential resonses that engineers are working on it. It may have been caused (on or after 23rd June) by a widespread attack on Microsoft servers. See two other replies I posted that have the link to the article.

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