I recently had my Comcast.net email address hacked, and I needed to change my password to avoid further access. It was really irritating--some scammer used my email address to send junk email to everyone in my contact list! In any case, I fixed up the email address, and changed the settings on my phone to match. I was able to receive email on the phone, but couldn't send. What's up?
As you probably know if you're a frequent listener. We're not fans of ISP. provided email accounts but that's not really the problem in this case. The problem is receiving and sending e-mail are two different servers on the server side and you've set the incoming server correctly but you never set up the outgoing server.
For some ISP's. These are different servers. So on your phone, you need to find your account settings for this email account. Look for something labelled SMTP settings. And under the SMTP settings, you'll need to enter the settings for your particular ISP. That may mean searching on the web for your ISP, like Comcast and the word SMTP. Those are four letters, and you'll find the settings I promise you.
Once you find them enter into your phone and you should be able to send e-mail again. You'll often need to provide your credentials as well because SMTP is a protocol that requires you to login, in order to send email. Good luck changing your phone settings.