Different settings are used for sending emails than from receiving email, unless you are using Exchange. Exchange email accounts can send email via Exchange but you can also choose to send email via an SMTP server instead.

Open the email account settings screen. (View) Then tap on "Outgoing Mail Server" to view the outgoing email settings screen.

Check with your email provider to see what your settings are for your SMTP server.

If your email server needs a username and password, turn on "Requires Username".

You can change advanced connection settings such as SSL and server port number in the "Advanced" section. If you are using port 25 then you will need to use a username and password. You may need to use port 465 or 587.

Tap on the "Test" button in the top right to test your account settings.