I have to fetch Exchange Mailboxes in batches of 100 (there are total 1m+ mailboxes in organization).  

I am using the following powershell command:  

`Get-Mailbox -ResultSize Unlimited`  

This gives me all the mailboxes which is taking long time. I can process the result in batches of 100 so I hit this command: `Get-Mailbox -ResultSize 100`.  

Seems to work fine but I'm stuck on how to bring the next 100 mailboxes. 

PS: You can assume that the mailboxes are static and no changes will be made on them for indefinite time...