2

I am using Thunderbird (Icedove) on Debian Wheezy. I have one imap account set up, and the the emails are synchronized with my imap server (i.e. I can read previously downloaded emails even when offline). All this is stored in my 

$HOME/.icedove/xxxxxxxx.default/ImapMail/

Now I have noticed that beyond that, my $HOME/.cache/icedove/ has around 80 MB. I don't know the purpose of the Thunderbird cache, the wiki says:

The disk cache mainly caches remote images and SSL certificates

What images and SSL certificates are they talking about? AFAIU, all emails are stored in my profile $HOME/.icedove/xxxxxxxx.default/ImapMail/. And how many certificates do they need to store? I am only connecting to one imap server.

Anyway, I would like to disable the cache completely:

browser.cache.disk.enable false

Will I lose any functionality, or notice any difference?

akira
  • 63,447
Martin Vegter
  • 40

1 Answers1

1

A cache usually stores information ("nearby") that will be needed ("probably") again later on. If you disable the cache, Thunderbird will just retrieve the information again from wherever it needs to be retrieved. So, in this aspect I do not see any deterioration of the functionality. Depending on the speed of your internet connection you might notice an increase of time thunderbird needs to render a mail, because it needs to retrieve things from the internets.

So, what things need to be retrieved? Not all resources are part of the email. This is especially true for html-emails which refer to external images, css and js. Even the resources embedded into the mail are embedded there in some sort of special encoding (base64 + a 'content-id', have a look at https://stackoverflow.com/questions/9110091/base64-encoded-images-in-email-signatures ). The HTML renderer of Thunderbird will need to fetch and/or decode these things to actually render the emails correctly. If you disable the cache, you will slow down this process.

Update:

When a page is loaded, it is cached so it doesn't need to be downloaded to be redisplayed. For e-mail and news, messages and attachments are cached as well.

http://kb.mozillazine.org/Browser.cache.disk.capacity

Community
  • 1
akira
  • 63,447