Auto detection of the character encoding was enabled but didn’t seem to be working – until I messed around with the settings and did this:

• Go to Tools > Options > Advanced > Config Editor and make sure that mailnews.force_charset_override is set to false
• Now right click on your Inbox and choose Edit > Folder Properties and make sure that the checkbox “Apply default to all messages in the folder…” is NOT checked.

Luckily Gmail allows you to access your mail not only through its website but through POP and IMAP too. To backup your email all you need do is set up an Email client such as Outlook, Outlook Express, Thunderbird etc. and download your mail onto your computer so you always have a local copy.

To do this you need to go to Settings in Gmail and look at the ‘Forwarding and POP/IMAP’ tab:

Gmail Settings

By enabling POP for all mail (even mail that’s already been downloaded) and configuring your Email client to download your mail using POP all your Gmail mail will be downloaded. Just run your Email client however often you need to and it will download new mail into your local copy.

You might also want to check the option ‘When messages ar accessed with POP’ and make sure that email downloaded with POP are left in your Gmail inbox plus check that your Email client is set to not remove the messages on the server when it has retrieved them!.