Enable TLS on smtp.aa.net.uk
This article as about enabling TLS in your email program when sending email through the AAISP email servers (smtp.aa.net.uk)
Why do this?
Firstly, it is good to understand what TLS is and why enabling TLS is good.
TLS stands for Transport Layer Security - it is similar to https web pages in that the data sent between your email program and the AAISP servers is encrypted and that you can be sure that you're talking to the correct email servers.
You can read more about TLS on the Wikipedia page
How to Enable it
Different email clients have different ways to enable TLS, usually it is just a tick box in the email account settings. Here are some pointers:
AAISP Webmail
The AAISP webmail will send email via TLS already.
Thunderbird & Icedove
Edit - Account Settings - Outgoing Server (SMTP) - Edit - Set "Connection security: STARTTLS"
Outlook
Tools - Account Settings... - Change - More Settings - Advanced - Set "Use the following type of encrypted connection: TLS""