On-site we have 3 of 4 AD servers (AD1,AD2 and AD4) with AD1 having most of the Operational Master Roles, however when AD2 goes down, freezes or reboots outlook says 'waiting for exchange server AD2', when exchange is on a different box completely. AD4 was just built from scratch and added hoping to get around this reliance on AD2 but it doesn't seem to have any effect, had a look through exchange settings and couldn't find any locations it points to AD2 and no other active directory servers.
Would appreciate some help on the matter, Thank You