I been playing around with some WebDAV code with Pocket IE (on a IPAQ)to display a screen that shows me the last 5 emails I received and the last 5 I sent. Because my IPAQ sits on my desk most of the day doing nothing I found this pretty handy as it alloys me to see at a glance which bit of email I need to take action on and what I've replied to recently. Geting the code to work inside of pocket IE was a little bit of a challendge had to switch to using Jscript and I found out that a few things that worked fine in the desktop version of IE don't work the way you really want them to (or at all) in the pocket version of IE but I did manage to come up with the following piece of working code. Basically what it does is performs two separate WebDAV queries the first one of the Inbox and then the Sent Items folder. I used the Range header to limit the result set of the queries to 5 rows. The Range header is pretty cool it kind of a sudo SQL TOP statement. I've added some simple HTML that displays unread email in a different colour and bold and the last part of the code sets up a ongoing timer which does a query of the mailbox every 25 seconds to see if any new mail has arrived or the read status of a mail has change. It does this by making another query of the inbox and then compares the received time of the last mail it received to the one it retrieved in the first query of that email along with the read status as well. If any of these are different then it initiates a page reload. The page itself is just a HTM page you copy to your IPAQ (after you mod the code to put in your mailbox and server you need to connect to). I've put a copy of the code up here
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