Hi simon330,
Since your emails are not going through when you send them, we recommend that you try the steps here: If you can’t send email on your iPhone, iPad, or iPod touch
To perform the steps in the article we suggested above, click and open the link, read the subheadings below, and try each step.
1) Check the Outbox for unsent email
2) Check your email address and password
3) Remove your email account and set it up again
The reason why we are recommending the steps above is because they will show you what to do if you can’t send emails from the Mail app on your iPhone.
If the original problem persists after trying the previous steps, please provide us with specifics on what you see for more help, and we will continue from there.
Thanks for using the Apple Support Communities.
Cheers!