Suddenly access to a foreign email account OK

[Phuket685]

I got a very strange problem. I'm using Outlook desktop and I am running several email accounts. Today I realized there is a complete new email account installed and u got full access to that email account although I didn't install it. The email account belongs to a person of the same company I have installed an account too. That person has global access right on the office365 account and office365 is the platform we mange our emails.
Can someone explain me why I suddenly have a foreign email account installed and what that could mean? Thanks

[#2]

Looks like someone granted you full access permissions to the said mailbox, with automapping configured. Automapping is a feature that will auto-add any additional mailboxes you have access to, so you don't have to add them manually. Best talk to your IT folks.

[#3]

Thank you very much Vasil. Very helpful answer. Does that mean, the person who gave me full access by automapping has also access to my emails?

[#4]

An admin can potentially access anyone's mailbox, emphasis on potentially :)

[#5]

@Vasil Michev: thank you very much Vasil

[#6]

@Vasil Michev: If I archive my emails on my harddisk on a file and delete the emails on the office365 Microsoft server, are they deleted for everyone or does Office keep a somehow back a global admin could still access?

[#7]

Depends. There are controls that can be put in place so that end users cannot inadvertedly delete messages. Again, talk to your IT folks :)