Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hi Gagan,
From the description, it looks like you are working on an Exchange Server configuration in Outlook.
If that is correct, then for issues related to Exchange Server configuration in Outlook, I would recommend you to post your query in the Exchange Forums for better results.
http://social.technet.microsoft.com/Forums/office/en-US/home?forum=outlook
If you have any other questions related to Office products, you can always reply and I’ll be happy to assist you.
Thank you