Running Exchange 2010 with 95% Outlook 2007 clients - the remainder is a testing effort with Outlook 2010. 340 users, 550 mailboxes total, no mailbox size restrictions. 180 Active sync devices via AirWatch through a SEG server. Virtual (vmware) Mailbox1 and Mailbox2 servers, virtual connection1 and connection2 servers. DAG reports healthy. All using EMC SAN storage and on AMD hosts.
Performance issues started last year and have consistently gotten worse except for a few weeks last month. Business growth has added about 100 users in the last year. 1/1/14 we had 225 users, 8/1/15 at 340.
We have 7 total mailbox databases, balanced on # of mailboxes not total size. Storage on the servers in nowhere near full (500+ GB available on each drive) and the DB's are spread across two local disks (D and E) M$ NLB load balanced on the cas servers...