Office 365 account associated with a hotmail account?

[Mark182]

We have a strange issue where we have a user who has a school e-mail address @sch.uk but when you type their name In the to box it's showing their school E-mail and their personal Hotmail account. This is happening for everyone who types the users name. I have had a quick look in the admin portal on their account and can't see anything, I've also had a look in the external contacts and there are not there.. Any ideas?

[nadeem]

At a guess, they've connected their two accounts together - its in options in the mail account

[angrycomputingteacher]

The user could of setup a alias account that is linked with the school email address.