Today I wanted to solve the issue of caching on the email signature banners once and for all. I don’t want any browsers or email clients to cache the image, so I started searching for solutions.

The best one I could find was this one:

<Files {FILENAME}>
FileETag None
Header unset ETag
Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
</Files>

So specifically to stop caching on the email signature file, I created an .htaccess file containing this:

<Files emailsignature.gif>
FileETag None
Header unset ETag
Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
</Files>

And saved the file here:

windeurope.org/wp-content/uploads/images/banners/.htaccess