How does your mailbox get connected when you travel to some other place from your region with office 365

How does your mailbox get connected when you travel to some other place from your region with office 365

https://blogs.technet.microsoft.com/onthewire/2014/06/27/dns-geolocation-for-office-365-connecting-you-to-your-nearest-datacenter-for-the-fastest-connectivity/  +Office 365 Worldwide Community

 https://web.facebook.com/office365wwc/