Thanks for the reply.
I was traveling and was on foreign networks. I am now at home and I can once again send emails. Do you know why foreign networks cause the problem?
Steve
This is what is known as the Port 25 relay problem. In the early days of the Internet, the founders thought that, while it would be necessary to use a password to receive your email, there was no need for one to send it. Using the analogy with regular mail, you need a key or something to open your mail box to retrieve your mail, but you don't need any such device to send paper mail.
So the original mail protocol didn't require a password to send mail. We all lived in an innocent world then when no-one would have thought of trying to send an email - purporting to have come from you - but, in fact, originating from a fraudster or criminal.
On your home network there are passwords that you need to use to access your broadband so, when you're sending from your home network, your email service provider knows that it's you who are sending the email - or at least someone who's sending with your permission.
But when you're on a foreign network they have no idea who you are because you don't need a password to send email. As a result, most email service providers will not accept email on the 'old' mail protocol (called Port 25 because this is part of the 'address' that this old protocol used to send mail).
If you want to send mail on a foreign network you need to change your email settings to use the newer protocol which has a secure login. This uses something called SSL. If you go to your email settings, you can enable SSL - choose the user name to be your email address and the password to be whatever password you use to collect your mail. When you switch to SSL the iPad should automatically switch the port number from 25 - which you will have seen there before you switched to SSL - to something like 465 (there are others too, but not 25).
Hopefully that fixes the problem. SSL will work on your home and foreign networks, so you should be able to try it at home before venturing out again.
Sorry I took so long to reply - I'm on vacation at the moment and not checking into iPad Forums quite so often.
Tim