For those of you who have ever wished to see what it takes to build some of the more advanced scripts that i post on this blog as part of the Connections Online conference I put together the following talk http://videos.devconnections.com/product/Exchange-Management-Shell-Beyond-the-One-Liner,5789-3.aspx . While i cant promise that this will teach you to be a guru in 60 minutes hopefully it may present a few different idea's and methods you may not have considered before and allow you to bash out a few more of your own scripts. There are also a lot of great videos on various aspects of Exchange posted by other Exchange MVP's that are defiantly worth checking out http://videos.devconnections.com/catalog/Exchange,390.aspx
If your getting an error such as Application is over its MailboxConcurrency limit while using the Microsoft Graph API this post may help you understand why. Background The Mailbox concurrency limit when your using the Graph API is 4 as per https://docs.microsoft.com/en-us/graph/throttling#outlook-service-limits . This is evaluated for each app ID and mailbox combination so this means you can have different apps running under the same credentials and the poor behavior of one won't cause the other to be throttled. If you compared that to EWS you could have up to 27 concurrent connections but they are shared across all apps on a first come first served basis. Batching Batching in the Graph API is a way of combining multiple requests into a single HTTP request. Batching in the Exchange Mail API's EWS and MAPI has been around for a long time and its common, for email Apps to process large numbers of smaller items for a variety of reasons. Batching in the Graph is limited to a m