Outlook rejecting emails from addresses on my safe sender list

Hi MaryH

I understand how confusing this can be, especially when the sender is already on your Safe Senders list and others are receiving the same emails without issue.

Have you already tried the Q&A Assist suggestions? In addition, to help me guide you better, could you please confirm:

• Are you signing in to the affected mailbox via Outlook.com with a personal Microsoft account, or is it a work/school account?
• Does the sender receive any bounce‑back / Non‑Delivery Report (NDR) when emailing your address?
• Have the messages ever reached your mailbox before, or has this issue only started recently?
• When you search “All folders” in Outlook.com, do any messages from this sender appear at all?

Looking forward to your reply so I can guide you further, Thank you for your understanding.

Safe Senders in Outlook.com and Outlook Web ensure that messages which reach the mailbox are not moved to Junk, but they do not override server-side filtering or rejections that happen before delivery. If the business messages are being rejected or dropped upstream, they will never reach the mailbox, even if the sender is on the Safe Senders list.

Use the following checks and mitigations:

1. Confirm the sender is really on Safe Senders/Safe Recipients
   • In Outlook.com / Outlook on the web:
     1. Select Settings (gear icon).
     2. Select Mail > Junk email.
     3. Under Safe senders and domains, verify the business address or domain is listed. If not, select Add safe sender, enter the address or domain, select OK, then Save.
        • This prevents messages that reach the mailbox from going to Junk.
2. Make sure the sender/domain is not blocked
   • In the same Junk email settings page, check Blocked senders and domains and remove the business address or domain if present.
3. Add the business address/domain as Safe Sender in classic Outlook (if used)
   • In classic Outlook for Windows:
     1. On the Home tab, in the Delete group, select Junk > Junk E-mail Options.
     2. On the Safe Senders tab, select Add, enter the full email address or domain (for example, contoso.com), and select OK.
   • Note: If the mailbox is hosted on Exchange/Exchange Online, server-side filtering can still reject messages before they reach Outlook, even if they are on the Safe Senders list.
4. Ask the sender (or their IT) to check for NDRs/bounce messages
   • If their system is getting Non-Delivery Reports (NDRs) when sending to the Outlook.com address, the rejection reason will be in that NDR. Their mail admin must fix any SPF/DKIM/DMARC or reputation issues indicated there.
5. Check rules and forwarding in Outlook.com
   • Sign in to Outlook.com in a browser and review:
     • Settings > Mail > Rules: ensure there is no rule deleting or moving messages from that sender.
     • Settings > Mail > Forwarding: ensure mail is not being forwarded away or deleted.
6. Verify mail is not going to Junk or another folder
   • Search All folders in Outlook.com for the sender’s address.
   • Check the Junk Email folder and any custom folders.
7. If messages still do not arrive
   • Because server-side filters may be blocking messages before delivery, and Safe Senders cannot override that, escalation to Microsoft support may be required. The sender’s admin should retain sample message headers and NDRs to provide to support.

References:

• Filter junk email and spam in Outlook
• Block or allow (junk email settings)
• Block or unblock senders in Outlook
• Options > Junk Email