I just added 4 servers to existing exchange 2003 environment , I have 2 cas servers on vm and 2 database servers in the dag . I migrated blackberry account to exchange 2010 . As soon as I rebooted cas1 server blackberry users cant receive emails . If I reboot cas2 after that they start receiving mail . I moved account back to 2003 , but now the same as soon as i reboot cas1 , all 2010 users don't get email , 2003 are ok . I am pooling my hair , what could it be . I did properly moved blackberry , disabled proper things in thoughteling policy . Any idea ?