It's driving me nuts.
There are no rules in Outlook, where else can I look for a solution?
That looks like some add-in interfering, check for those or simply run Outlook in safe mode ('Outlook /safe' in the run box or hold the CTRL key when launching it).
I asked my IT guy who manages my 365 account and he says there are no rules.
If I log in on my Mac, there are no local rules or exchange rules.
@Vasil Michev It's not my desktop version of Outlook. If I send it from Outlook on my phone, it still ends up in OneNote.