ISP SMTP servers
How can I send e-mail from home? My ISP says I can't use the UCL SMTP server.
An increasing number of Internet Service Providers (ISP's) now only allow their users to send e-mail through their own system, rather than through UCL, using the e-mail address you got when you registered with their company.
These ISPs block access to external SMTP servers (the server used for sending messages), including UCL's SMTP server: smtp2-server.ucl.ac.uk, as an anti-spamming measure, to try and prevent junk e-mail being sent.
If your ISP has done this, you will not be able to send messages from your UCL e-mail address while you are connecting to the internet through your ISP. You will need to send e-mails from your ISP e-mail address.