This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(128, 8%, 22%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EA%3C/text%3E%3C/svg%3E)
Hello, today I received a weird mail on my office 365 mail, but I never use office software and never contacted this company, did I get hacked ? What should I do, thank you.
"Your message to ******@americana-food.com couldn't be delivered.
The group aemktpeetscoffee only accepts messages from people in its organization or on its allowed senders list, and your email address isn't on the list."
| Original Message Details | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Created Date: | 6/3/2025 12:00:27 PM | <br> | --- | --- | <br> | Sender Address: | *my mail* | <br> | Recipient Address: | ******@americana-food.com | <br> | Subject: | Peets Enquiry | ||
| Error Details | |||||||||||||||
| Error: | 550 5.7.133 RESOLVER.RST.SenderNotAuthenticatedForGroup; authentication required; Delivery restriction check failed because the sender was not authenticated when sending to this group | <br> | --- | --- | <br> | Message rejected by: | DU4PR01MB10741.eurprd01.prod.exchangelabs.com | ||||||||
| Notification Details | |||||||||||||||
| Sent by: | DU4PR01MB10741.eurprd01.prod.exchangelabs.com | <br> | --- | --- |
| How to Fix It |
|---|
| It appears you aren't in the same organization as the group (or a sub-group) you're sending to or your email address isn't on the group's allowed senders list. Ask the owner of the group to grant you permission to send to it, and then try again. If the group belongs to a different organization than yours, contact the organization's customer service department for assistance. If the group is in your organization and you don't know who the group owner is, you can find it by doing the following in either Outlook on the web or Outlook: |
| <ul style="margin-left: 40px"><li><p>Open your Sent folder and select the original message.</p></li><li><p>If you're using Outlook on the web, select the group name located on the To or CC line. If you're using Outlook, double-click the group name located on the To or CC line.</p></li><li><p>In Outlook on the web, from the pop-up dialog box, choose Owner. In Outlook, choose Contact. The owner's name is listed under Owner.</p></li></ul> |
| The owner of the group may have intentionally chosen to restrict who can send messages to it, and they may not want to adjust the existing restriction. In this case, you'll have to contact the group members by some other means, such as sending an email message to their individual email addresses or contacting them by phone. |
Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(204.8, 84%, 29%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EAS%3C/text%3E%3C/svg%3E)
P.S. "...someone used your e-mail to send their..."
I mean, I replaced the return address with yours, rather than using your mail or device to send the letter (I use an online translator, so there may be inaccuracies in the translation of the meaning).
Hello.
Most likely, someone used your e-mail to send their letter to this company, changing their own address to hide the true sender.