Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hi ArunPalanisamy3696,
In Office 365, there is a recipient limits that prevent users and applications from sending large volumes of email per day. You can refer to the article below for the detailed limit.
If you have exceeded the limit, there could be a delay for you to deliver the emails. If not, please provide the following information so we can further investigate this issue:
- As you said, only few users have this issue when receiving emails from the distribution group. Please send one delayed to us for further research.
- The entire message trace report for the delayed email.
I have sent you a private message to collect the information above. You can access it via the link below:
https://answers.microsoft.com/en-us/privatemessages/list
Regards,
Yang