Forum Discussion
Exchange Online now blocking whitelisted domain
From what you've written I think you are in the wrong place. If you look at my post, while I'm talking about the anti-spam policy page, I was not talking about editing the Anti-spam inbound policy" !
Here again with additional clarification where that is:
Email & collaboration ⇒ Policies & Rules ⇒ Threat policies ⇒ Policies: Anti-spam ⇒ click "Connection filter policy (Default)" ⇒ Add IPs or IP Ranges in CIDR format in "IP Allow list"
In my screenshot there are way more IPs allow-listed than I need but I can't be bothered to clean up the list until things work again. Since my change was done no additional mails were rejected but I can't be sure since my change was done roughly at the end of the business day and mail volume in the evening is lower than during the day.
UPDATED: Thanks for the additional info. Please post if your updates to the Microsoft Defender policies fix the problem. According to my notes, I've been to the MS security page in the past (security.microsoft.com in ⇒ Policies & Rules ⇒ Threat policies ⇒ Anti-spam policies), and set the "Anti-spam inbound policy (Default)” to allow blocked senders and domains”. However, when I now click on the Security option from the Exchange 365 admin menu, the page that opens doesn't seem to have a "Policies & Rules" option. Am I missing something obvious?
Also, over the last day ALL messages from our Linux server are now being blocked. I hope Microsoft eventually sheds some light on what's going on...
From what you've written I think you are in the wrong place. If you look at my post, while I'm talking about the anti-spam policy page, I was not talking about editing the Anti-spam inbound policy" !
Here again with additional clarification where that is:
Email & collaboration ⇒ Policies & Rules ⇒ Threat policies ⇒ Policies: Anti-spam ⇒ click "Connection filter policy (Default)" ⇒ Add IPs or IP Ranges in CIDR format in "IP Allow list"
In my screenshot there are way more IPs allow-listed than I need but I can't be bothered to clean up the list until things work again. Since my change was done no additional mails were rejected but I can't be sure since my change was done roughly at the end of the business day and mail volume in the evening is lower than during the day.
I just opened a console session on the server and successfully sent an email to the exchange online distribution group that we use to monitor the server. Hopefully, in the morning I'll have the full complement of emails that we are used to getting. Thank you very much for your help, and I hope this resolves the issue!
- Thanks for clarifying the changes, and I have now added my server address to the Connection Filter Policy. Currently, I'm not getting any messages from the server. Have you had any improvement on your end?
- All my mails were delivered today, none rejected. Probably because of the IP allow list, although I did simultaneously submit it for unblocking at other Microsoft Websites. But it probably was only the allow list change that solved it.