External people cannot post to our group
By default Microsoft 365 distribution groups block external senders. Deliberate to keep spam out, sometimes inconvenient.
Try this first
- 1Decide first: do you really want anyone to post to this list, or just specific partners?
- 2For specific partners: have your admin add those addresses to an allow list on the group.
- 3For open groups: enable 'allow external senders' on the group itself, not on the whole tenant.
- 4Tell the members the group is open now; so they understand why an odd message suddenly gets through.
When to bring us in
Admin access needed to change this. Not sure where that lives, or unsure if you really want it open? Give us a call, we will think along.
See also
- Our emails land in spam for some recipientsAlmost always an SPF, DKIM, or DMARC setting that is wrong or missing, or a sender name that mimics a well-known brand.
- Someone reports receiving phishing emails "from us"Read: spoofing. Someone is abusing your sender name, not necessarily your actual mailbox.
- An email bounces (NDR): delivery failedThe NDR text usually states the exact reason. Reading it is step one.
None of the above fits?
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