Error message when trying to send email on 3G wireless dongle

[#1]

Have read thru the long posting about SMTP authentication, but am totally baffled, and don`t know what it is on about.   so maybe, I need some help....!..
have tried to send a couple of emails, (different addressees) from my holiday location, using a wireless dongle 3G. to connect to the net...
I can receive my emails as normal but when I try to reply,  The transmission bar takes a long time, and then produces the following error message

Quote

An error occurred sending mail: The mail server sent an incorrect greeting:  Cannot connect to SMTP server 212.159.8.107 (212.159.8.107:25), connect error 10060.

Using Thunderbird (up to date version)... with Windows Vista Home Premium, and Zone Alarm, and Avast  
If the problem is being caused by lack of SMTP authentication.... can someone please point me to the "instruction manual" so I can have a go at setting that up..
thanks.

EDIT EDIT EDIT EDIT EDIT
Just used the Webmail system, and it sent the message no problem... so what is going wrong? 

[#2]

The instructions for setting up SMTP authentication on Thunderbird are in the following guide "Send mail from any connection (SMTP Authentication)".
However if your mobile provider blocks external connections to port 25 even that will not work. In that case you would need to use your mobile provider's relay server.

[#3]

Three doesnt like sending straight e-mail, I had to resort to webmail on my recent trip

[#4]

Thanks for the linky...
As PP says.... if Three won`t let me send email, then I`ll do it via Webmail...
Was just a bit (?) confused when it would not let me send , but would receive in the normal way...

[#5]

just tried looking at Three's atrocious web site, no clue there as to how you send mail and what port they use

[#6]

It is a bit of a pain in the posterior.
In short, Three ban any sending of mail over SMTP unless it's via their own mail server. If you want to use Thunderbird rather than Webmail, go to Tools | Account Settings & scroll right to the bottom to find Outgoing Server (SMTP). Add an additional server - smtp-mbb.three.co.uk
Leave all default settings. In particular, do not set up authentication.
Now, when connected by Three, come back to this same screen & change the default server from Plusnet to Three. Mail will then be sent using their server. It will still be sent 'From' whatever email address it always is. When back connected to Plusnet, switch the default back again.
Very simple once you know how, but it was like drawing teeth to get the information that a) it was necessary & b) what actually needed to be set.

[#7]

Thanks for the instructions,Simon,    Seems to be a lot of bother just to send the occ email via 3,  so will use the PN Webmail system,  got it bookmarked, so don`t have to change any settings ....
Back home now, so not needed.
However... your instructions are now on the PN Forum, so should be easy (?) for someone to find, should they need them...
Thanks