I have important emails in my Outbox but not getting a message why they are not going, wifi is strong so why are they not sent?

My emails are not being sent they are staying in my outbox, my wifi ius strong, there is no reason why they are not going.  I even deleted photos in case that was the reason but even without photos they are stuck in my Outbox.

The usual culprit, when you can receive but not send, is your anti-virus/firewall application. Temporarily disable that and see what happens.