Since you said “If i turn off the wifi on my phone i can connect through cellular no problem” it sounds like the mail server thinks the IP address of your office network is making too many requests. This could be caused by many things.
One thing you could try before contacting support is to connect to different wifi, and verify that things work normally (that would be our guess what will happen based on what you have said so far). Once you have confirmed the office network appears to be blocked on the mailserver, then you could use a service like http://www.whatismyip.com/ to determine the IP address of the office. Visit that from the desktop with Outlook and from your phone with office wifi turned on. You should get the same IP address on both. Now open a ticket and ask support why your office IP is blocked on the mail server.