Trying to receive emails and senders are telling me they can’t send due to being rejected

Josh Miles 0 Reputation points
2026-09-17T10:30:51.2433333+00:00

Can’t receive emails from some senders, they are telling me that the email is rejecting. Been ongoing emailing them for the past 24 hours and it must be something on my end/ hotmail end.

Outlook | Web | Outlook.com | Email
0 comments

2 answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Hornblower409 15,920 Reputation points
    2026-09-18T05:07:00.5666667+00:00

    @Josh Miles said

    Can’t receive emails from some senders, they are telling me that the email is rejecting

    The people who are trying to send to you should be getting a Non-Delivery Report (NDR) from the Microsoft Mail server. Please ask them to look at the NDR and tell you what rejection code they see. It will be something like "5.0.350", "5.1.10"

    Once we know the code we can help you fix the problem.

    Was this answer helpful?

    0 comments

  2. AI answer

    2026-09-17T10:31:09.73+00:00

    If some senders get a rejection or bounce-back, this is often not a mailbox setting on the Hotmail/Outlook.com side.

    Check these items first in Outlook.com:

    1. Check Junk Email settings and the Junk Email folder. If valid messages were marked as junk, move them back by right-clicking the message and selecting Mark as not junk.
    2. Check whether email forwarding is enabled.
    3. Check whether any rules are moving or hiding messages.
    4. Check the Other tab and make sure filters are not hiding messages.
    5. Check mailbox and Microsoft cloud storage usage. If cloud storage is full, Outlook.com cannot send or receive email, and messages sent while storage was full are bounced back and unrecoverable.
    6. If the account password was changed recently, update it. Accounts can also be temporarily blocked because of unusual sign-in activity.

    If senders are receiving a non-delivery report, the exact error in that report matters:

    • If the rejection mentions SPF fail or that the sender domain does not meet authentication requirements, the sender must fix their domain email authentication. That is not something that can be corrected in the mailbox.
    • If the rejection says the sender IP is blocked or shows 5.7.511 Access denied, the sender needs to use the Microsoft delist process for their sending IP.
    • If the rejection says Microsoft temporarily restricted mail from the sender IP, such as 451 4.7.550 Access denied, please try again later, the restriction is temporary while the traffic is evaluated.

    If only certain senders are affected and others can still deliver mail, that strongly points to a sender-side issue such as SPF/authentication failure or poor sending IP reputation, not a problem with the mailbox itself.

    A practical next step is to ask one affected sender to send the full bounce-back error text. That will show whether the issue is:

    • sender authentication failure,
    • sender IP blocklisting or throttling, or
    • a mailbox-side filtering or forwarding issue.
    AI-generated content may be incorrect. Read our transparency notes for more information.

    Was this answer helpful?

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.