Fastmail (and nearly all web-based services) requires that cookies are enabled during a session. After viewing the cookies stored on my PC, here is what I believe is happening:
- If you allow persistent cookies to be saved for Fastmail, then if you close all Fastmail windows in your browser and then later go to www.fastmail.com, the unique settings you last saved for that browser on that particular PC are used for the text size choice (only) in Settings>Customize>Preferences>General. If you log in on a different PC, it can have different saved settings for those items.
- If you clear your persistent cookies between Fastmail sessions, then Fastmail uses the default settings for the text size (only) when you start a new session.
- The text size cookie allows you to use a different text size on different PC's to accommodate differing display sizes. As far as I can tell, this is the only setting which is saved locally (in a cookie) as opposed to the other (globally saved) settings.
Bill