Just give me a few minutes to look through all of your original post. I will try and help if I can. Mobile's are second nature to me as I have worked for O2 & 3, but give me a few mins.
Rest assured there is always somebody about on CF to help people out.
-Edit-
Ok this looks like a POP3 Outgoing setting that is incorrect or not present on your SE w950i handset, which would explain why you are unable to send emails. Your incoming settings look fine as you can receive emails.
Who is your mobile phone network provider? O2, 3, Voda, Orange, T-Mobile, Virgin???
What is the second part of your email address (@ntlworld.com, @blueyonder.co.uk)?
You may also wish to consult the w950i Product Manual which you should have. If not you can download one from
here.
Its in .pdf format so you will need adobe acrobat reader to view it. Refer to the section regarding setting up Internet,email & MMS (Page 65 of the manual). Have a read through that and follow the instructions given. I think all you will need are the outgoing settings for your mail provider, in this case Virgin Media. Which you should have or you can obtain these over the phone or if some kind person, can post here.