I have a large number of emails that I want to reply to as fast as possible using the Microsoft C# Managed API for Exchange Web Services (EWS).
Batch operations is the way to go on getting speed out of EWS. I can see batch operations for Create, Update, Move and Delete. However I don’t see how I can create reply objects in a bulk way.
The code to reply is typically Bind to the item using its ItemId Call CreateReply Call SendAndSaveCopy
CreateReply returns a ResponseMessage object, however all the batch API methods use Item objects and so I cannot invoke them for these reply messages.
Is there any way to reply to many messages in a single EWS API call?
Its possible in EWS as the Reply Method is just a CreateItem operation which you can batch, In the EWS Managed API (which is just a client side libary) however the classes won't allow you to do it. So if you switch to using WSDL proxies or Raw SOAP it should work fine or you could modify the EWS Managed API source to make it work https://github.com/OfficeDev/ews-managed-api (however that would be a lot more work).