Enable TLS on smtp.aa.net.uk: Difference between revisions

This article as about enabling TLS in your existing email program when sending email through the AAISP email servers (smtp.aa.net.uk). If you are setting up an email program from scratch then simply select/tick the options to use TLS or STARTTLS. This page gives help when you want to edit an existing account to enable TLS.

==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 is sent securely. This is good as it prevents eaves droppers between your computer an our servers from seeing your data (and even your username/password credentials if sending using authentication). TLS also helps confirm that the server you are talking to really is our server and not an impostor on 'man-in-the-middle' as the certificate is tied to the name 'smtp.aa.net.uk' and your email program should give a warning if the certificate does not match.

[[File:SMTP-TLS.svg|none|frame|Enabling TLS is the connection between you and the AAISP email server, the rest of the connections are out of our hands though.]]

It is useful to know that enabling TLS in your email program only affects how you send email to our servers. Once we have received your email we will then send it onwards to the recipients email server. Where possible our servers will also use TLS but if the recipient server does not support TLS then the email will be sent without any encryption. Beyond that it's outside of your or our control.

Enabling TLS is different from encrypting your actual message. TLS will encrypt the data between you and the AAISP mail servers - hiding the metadata and so on. If you want to ensure only the recipient can read your message then this can be done by encrypting the message with PGP or S/MIME.

You can read more about TLS on the [https://en.wikipedia.org/wiki/Transport_Layer_Security Wikipedia page]

== Recommended Settings ==

Modern email programs that you use on a computer or mobile device should be capable of supporting modern TLS ciphers - if not then the program is probably very old, out of date and will have other problems. It would be best to upgrade - Mozilla's Thunderbird is a good choice.

Some devices such as webcams, DVRs, and so on may lack TLS features. If this is the case, then do check for firmware updates.

If you are sending from outside of our network, ie using another broadband or mobile provider, then you will be using authentication. This involves sending your username and password across the internet to our servers. This really should be done with TLS enabled as otherwise your credentials could be seen by other people.

At the moment, for legacy reasons, we still do allow customers to send authenticated email without TLS - this is a risk and it is a feature we want to disable in the near future. We will then only allow authenticated email over TLS. If a customer needs to send email when not using our broadband services and cannot support TLS then we'd have to suggest to use the email services provided by the ISP.

We do allow customers on our broadband services to send email without authentication and this can be with TLS enabled or disabled.

Here is a summary table:

!colspan="3"|Sending Email through smtp.aa.net.uk

|Optional, but Recommended

|Optional, but Recommended

Mutt will your your machine's local MTA (eg sendmail, exim, postfix etc) - so look at the documentation for that for more information.

<syntaxhighlight lang=shell>

<syntaxhighlight>

<syntaxhighlight>