Currently Being ModeratedJul 27, 2013 10:45 AM (in response to cliffcrusher)
I found an article with useful information about the getting "Mailbox Locked" on your devices:
Thank you for using Apple Support Communities.
Currently Being ModeratedAug 25, 2013 7:53 PM (in response to sheila_m.)
It seems that I need to update the webmail, Apple Mail, Contacts and Calendar apps simultaneously in my MB Pro and in my iPhone after changing it in webmail. This solves my locked out problerms.