Snoop, my bestie.
Your emails are being identified by Outlook as Spam, and quite frankly I’m offended that Outlook are classing my best friend as, well, a horrible tasting weird canned meat.
(Full disclaimer - never had Spam but the smell is disgusting, and I’m not even entirely sure it can be classed as meat )
In my history with emails going to Spam, as you progress it tends to fix itself; but having the heads up that emails are going into Spam can help you fix issues.
I can write a strongly worded letter to Outlook if you want - but I don’t think we need to break these big guns out just yet