This post discuss an issue where connections to Outlook Anywhere are extremely slow or fail completely. This issue also affects other sites that use the SBS Web Applications app pool. The reason this happens is due to the default setting of ASP.net 2.0’s default maximum concurrent requests of 12 per CPU. When using RPCProxy which is used by both Outlook Anywhere and TS Gateway, the connections are asynchronous which can cause you to hit the limit of 12 pretty fast. For more detail on thread usage and this limit please read.