outlook freezes only when dealing with 1 single user email address

[alindabery]

when I open an email, CC, TO, reply or forward to a specific email address (co-worker) my outlook freezes. In outlook.com It does not happen. also it is not immediate. it takes 3 tries before it freezes. open, create, reply or forward. From then on it freezes instantly on any emails that contain the users address. Very frustrating. I am in the USA. He is in the UK. It appears to happen only to the users in the USA(3 confirmed), my coworkers outside the USA are not freezing when using his email address. following tried to no avail:
1 delete all email with user's address
2. move all remaining emails to a pst. then ran outlook no pst
3. turned off caching.
4. disabled, then uninstalled antivirus when disabling didn't work.
5. all software: office and windows updated


6. disabled all add-is
7. run in safe mode (yes it freezes)
8. create new outlook profile
9. deleted and created new logon profile to computer
10. turned off auto complete
11. repaired (quick then full), then uninstall/reinstall office
12. turned off animations
13. turned off hardware exceleration.
14. tried multiple computers.