We are not receiving emails from Efax Corporate

Caring Hands Services INC 0 Reputation points
2026-10-06T16:52:22.44+00:00

Good Morning,

Our faxes from EFAX corporate are not coming through in our inbox. We contacted Efax Corporate and they confirmed that the email was bounced back from Outlook end. Can you please assist us.

Outlook | Web | Outlook on the web for business | Email
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  1. Kai-L 19,920 Reputation points Microsoft External Staff Moderator
    2026-10-06T17:12:08.6666667+00:00

    Hello Caring,

    Missing faxes can hold up important work, so I understand the urgency. Unfortunately, as a forum moderator, I am not able to check your mailbox or mail flow logs to diagnose this directly. My role here is limited to providing general guidance you can apply from your side. Since eFax confirmed the message was bounced, the most useful next step is to get the full bounce message (non delivery report) from them. Please ask eFax for:

    1. The full bounce message, including the SMTP error code (for example, 550 5.7.1) and the diagnostic text
    2. The sending address they use
    3. The date and time of a failed delivery, including the time zone

    Your Exchange administrator can then trace the message in the Exchange admin center:

    1. Go to Exchange admin center and select Mail flow > Message trace.
    2. Search using the eFax sender address, your recipient address and the delivery time.
    3. Check whether the message was rejected, quarantined or delivered.

    It's also worth checking the Quarantine page in case the faxes were held there.

    If the message trace shows no record of the message, it may have been rejected before it reached Microsoft 365, for example by another email security service in front of your mailbox. In that case, the error details from eFax will show which server rejected it. Please avoid adding eFax to an allow list until your administrator has reviewed the bounce details and confirmed the exact sending domain. Broad allow list entries can bypass useful security checks.

    If you'd like to share the bounce message here, please mask any email addresses or other personal details first. The error code alone will help narrow this down.

    I hope this helps. Looking forward to your reply.

    If the answer is helpful, please click "Yes" and kindly upvote it. If you have extra questions about this answer, please click "Comment".  

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