Outlook Web Access (OWA) does not have a security line. The only way that I have found is to configure a second user to have rights to this account, give this new user enough rights to open the account and share the target user's calendar using Microsoft Outlook.
To assign permissions on individual folders like the Calendar, you would need to log in as the user. Alternatively, you could use ExMerge to export the user's calendar folder/mailbox and let the other user have the .PST file (or copy of his/her mailbox).
Do you have comments on this Ask the Expert Q&A? Let us know.
Related information from SearchExchange.com:
Dig Deeper on Exchange Server setup and troubleshooting
Related Q&A from Bharat Suneja
Get tips on how to download POP3 email to Microsoft Outlook mailboxes in a Microsoft Exchange Server setup. Continue Reading
Find out how to configure an auto-reply message for distribution groups linked to Exchange Server email addresses. Continue Reading
An Exchange Server administrator seeks advice on how to prevent users from deleting the unified messaging folder, which stores their voice messages. Continue Reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.