Memory leaks when running MailSim with Client SDK provider

[v-am]

When you run MailSim with Client SDK provider for O365, the memory used by the app (as observed in Task Manager or Resource Monitor) continuously grows. Eventually, MailSim fails with "Out Of Memory" exception.

It seems that initially memory grows pretty fast, but then the growth gradually becomes slower.

In contrast, with Http provider, the memory remains about the same even after more than 24 hours run.

It appears that most of memory increase is related to queries for mail items; by default, MailSim would get 500 items for those operations that require random mail selection.

The only suspicious thing I noticed when trying to use Visual Studio memory profiler, is that SDK Message object (the one that represents mail items) has circular reference to itself.