If you've been
Outlook not receiving emails
from Outlook on iPhone, you may have accidentally deleted them or discarded them. In order to fix this issue, open the Outlook app and delete any old emails from the account. If the email still isn't in your inbox, try deleting it from your iPhone. If this doesn't work, try deleting unwanted emails. You can also use the Sweep feature, which deletes any emails from an email sender without you even having to open them.
For kniw more - www.reddit.com/user/emailscrunch/comment...ook_app_not_syncing/