Small startup company, exchange account for Off 365: In Outlook for Mac 2011, my sent emails do not go to Sent Items folder; they show up in my inbox. This just started.

BACKGROUND:  My small startup company bought Office 365 last September/October.  We got everybody on by about October 20.  We put it on each one's personal Mac or PC.  I have a MacBook Pro.  We have Outlook for Mac 2011.  We have an exchange account.

ISSUE:  On March 31 in the afternoon, the emails I sent out began to NOT appear in my Sent Items folder.  Rather, they popped up in my Inbox as an email sent from me.

Since then, every email I send does NOT show up in the Sent Items folder, but in my Inbox.

The emails do go to the person I send them to, successfully.  No problem there.

Possible related issue:

When I click on the Email icon, upper left, to create a new email message, I get the form, eady for me to start creating.  As normal, the "From:" window at the top has my name in it already, HOWEVER when I click on the tiny arrows at the far right of the window, two other names appear.  One is my name on my other email account, which I have for personal emails, but the third name is the name of a co-worker!  It appears to give me the option of sending out an email "from" her.

Please advise how I fix this.  Thanks!