He have recently upgraded to Exchange 2013 moving from 2007, all users have now been migrated and everything seems to be running ok internally.
Outlook anywhere however is taking an age to connect to the server from users outside the network.
Some users cannot connect but that may be a different issue.
Everything seems to be setup correctly and I tested with Microsoft Remote Connectivity Analyzer which it passed.
With Exchange 2007 it used to be pretty instant.
I cant see any reason for it so would like some help in case there is something ive overlooked.