The mail app is not doing this.

Iphone all emails going to junk. Click mark, then click “move to junk.” subsequent. Web legitimate emails filtered as spam. Web press the menu key, select settings, and then select general settings.

Web as far based on my knowledge, in exchange online, the message will be marked as spam and moved to the recipient's junk email folder if spam filtering is. It's the mail server's spam filter. Web restart your iphone.

Web to make sure future messages from the same sender are marked as junk, you can report messages as junk in the mail app. Web open the mail app from your iphone’s home screen. If you selected one message:

Web #1 yesterday i updated my iphone to ios 13. You need to login to your provider's webmail and update the settings. Web on your iphone, go to settings > passwords & accounts and tap the account associated with the email address you want to adjust.

As i stated in my question: If you selected multiple messages: Mark as junk mail, but leave it in my inbox:

Highlight junk mail with color and leave it in your inbox. Press your account name in the top left corner. If the issue persists after trying the steps above, remove the mail account from your device, add it back and then test again.