Your mailbox will migrate to the Houghton Hong Kong Exchange 2013 environment beginning at 7:00 PM UTC on Friday, April 3, 2015.
The OWA page will be updated to the following URL: https://ap-webmail.houghtonintl.com/owa
You must have any Outlook clients accessing the new Exchange environment fully patched via Windows update. Unpatched Outlook clients may have issues connecting or continually prompt the end user for their password.
On mobile clients, iPhones should auto-update the mailbox to the new URL, but any Android clients will need to be re-setup