Since there are some limitations for Exchange 2013 Public Folders, we will focus this little note on the User Logons supported limit, which is 2,000.
I briefly mentioned this 2,000 user logons limit on the article about Public Folder limits increase since Exchange 2013 CU8 on a previous blog post.
In Exchange 2013, you should plan for a number of PF mailboxes according to:
- the volume of PFs you have as the limit is 100GB per PF Mailbox – and 100 PF mailboxes max – reserve 1 for hierarchy updates, that leaves 99 PF mailboxes max for content storage
- a target number of Client Logons you’ll have
Knowing that a single user can issue more than 1 client logons at a time because these are accessing the PF Hierarchy + accessing PF content which is hosted on another PF Mailbox + other content on other PF Mailboxes … And, knowing that if a user accesses PF content that is on his “default PF Mailbox”, that counts for 1 concurrent user logon … so that’s not an easy exercise !
Read more at source: http://blogs.technet.com/b/samdrey/archive/2015/06/13/exchange-server-2013-planning-for-public-folders-mailboxes-according-to-user-logon-limits.aspx