Hi @Boopathi S ,
I noticed you are working with Outlook desktop client, is it right? If so, I have tried to perform some tests with Microsoft 365 account on my Outlook 365 version 2105(Build 14026.20270):
- create a meeting and send the invitation to a shared mailbox and other mailboxes,
- login to a mailbox that full access to this shared mailbox and open the invitation in shared mailbox
- click reply all option
But I found all recipients could be displayed normally on ‘To’ and 'Cc' field, which seems to I couldn't reproduce your issue.
So in order to further confirm if the issue is related to your client or mailbox, did it occur on any specific meetings' invitations in the specific shared mailbox? If it occurred on this shared mailbox only, could others who has full access permission to it reply the invitations normally? And could the issue be reproduced on web mail?
Please kindly provide us with more information about your issues(such as detailed client version, test results etc.), so that I could perform more targted tests on my environment.
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