Some emails to me are being blocked improperly.

Jonathan Segal 0 Reputation points
2026-11-08T14:30:00.0533333+00:00

Some emails to me are being blocked for no reason. It has been going on for some days now and it is always the same people, I think. I can’t be sure because I wouldn’t know if other emails are being blocked

Outlook | Web | Outlook.com | Email
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  1. EmilyS726 279.2K Reputation points Independent Advisor
    2026-11-08T15:04:31.02+00:00

    Hello

    I am seeing a sudden increase in similar reports from other users in this forum as well.

    Unfortunately, I cannot find any official information from Microsoft acknowledging this issue. Microsoft's published requirements for SPF, DKIM, and DMARC apply to senders sending more than 5,000 emails per day. However, based on the sudden increase in reports from the last few days, I suspect these requirements may now be affecting low-volume senders as well. This is just my observation, not something Microsoft has officially confirmed.

    I helped several users with this issue yesterday in this forum. One interesting thing we noticed is that email headers may show DMARC as passing, even when the sending domain does not have a published DMARC record. We were able to identify this by checking the domain using a free tool such as https://mxtoolbox.com/.

    In some cases, once the missing DMARC record was properly configured and verified, emails started coming through again. But please know that this needs to be fixed on the senders end. There’s nothing you can do as recipient.

    For this reason, I strongly recommend having your senders check their SPF, DKIM, and DMARC records for the affected sending domains.

    If you need help checking these records, I am happy to do so. I would just need to know the sending domain name. You do not need to share the full email address.

    Note: These are non-Microsoft websites. They appear to provide useful information, but be cautious of advertisements or downloads for potentially unwanted software. You do not need to download anything to use the domain-checking tools.

    Also, news article about this issue: https://www.neowin.net/news/microsoft-outlook-spf-validation-error-blocks-email-sending-and-receiving/

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  2. AI answer

    2026-11-08T14:30:17.5633333+00:00

    If the missing messages are not in Inbox, Junk Email, or the Blocked senders list, they may be getting rejected before delivery rather than being moved into the mailbox.

    Start with the mailbox checks that are available in Outlook on the web / Outlook.com:

    1. Open Settings > Mail > Junk email.
    2. Under Blocked senders and domains, make sure the sender address or domain is not listed. Remove it if present.
    3. Under Safe senders and domains, add the full sender address and the sender’s domain.
    4. Save the changes.

    If the sender is already not blocked and messages still never appear in Inbox or Junk Email, the likely cause is sender-side authentication or reputation filtering. In that case, the sender should check whether their mail is being rejected because of SPF, DKIM, or DMARC issues. Outlook.com can refuse mail during the initial delivery attempt, so nothing appears in the mailbox.

    Useful checks:

    • Ask the affected senders whether they receive a bounce or rejection message.
    • If they do, the diagnostic code in that message helps identify why Outlook.com rejected the mail.
    • If only one company or domain is affected, that points more strongly to a sender-side issue.

    Also note:

    • In Outlook on the web / Outlook.com, blocked messages are normally moved to Junk Email.
    • Junk email is automatically deleted after a retention period, depending on the Outlook experience described in the support articles.
    • The blocked and safe senders lists can contain up to 10,000 addresses or domains.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

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