I cannot send emails with Evolution on my Netbook Ubuntu 10.10 netbook version

Who is your email provider?

I prefer Thunderbird. It's really a professional tool and it doesn't make any problems.
Peter

My Provider is Aliceadsl.fr

can you ping smtp.Aliceadsl.fr

?

I have done this but still getting a problem. Under send emails should I also tick the box for server authentication. Then below it states PLAIN or should I use Pop before SMTP? What does it mean by username what should I write in that box? Do you think that this this the cause of the problem? Many thanks

Is this still an issue for you?

Checking with your email provider's web site:
http://www.alicebox.fr/assistance/1487-alicebox-les-adresses-de-serveur-de-messagerie-les-adresses-pop-et-stmp-alice.html

it seems that they do not mention that the require Pop before SMTP. The username should be given by your email provider. But (if my French is not too far off) that site does mention that it does /not/ support encryption via TLS & SSL. Do you have encryption configured? If so could you try to disable it and send a harmless message?

Be aware that if you don't use encryption (which this provider doesn't seem to offer) that anyone between (potentially virus infected Hotspots/Access points and ISP between those access points and the smtp server) can spoof the contents of you mail including e-mail addresses for spam harvesters.

I'd consider contacting your provider to request a secure access or switching providers... then again my French is not that great anymore so I may be mistaken.

If that doesn't help, please try to install the nmap package (port scanner) and post the results of:
nmap -PN -p 25 smtp.aliceadsl.fr

it should say something like:
Starting Nmap 5.21 ( http://nmap.org ) at 2011-01-12 23:12 CET
Nmap scan report for smtp.aliceadsl.fr (212.27.48.4)
Host is up (0.068s latency).
rDNS record for 212.27.48.4: smtp.free.fr
PORT STATE SERVICE
25/tcp open smtp

if you can reach the smtp port from your netbook.