Moving this topic to the TB for Android queue.

As it stands, some features you may require are unavailable in the current Thunderbird for Android version (v15). The teams are currently redesigning the user interface and have removed font related customisation, including size while this work progresses. Alternative options are being worked on to bring back customization in a future update. You can find discussions on the topic, along with draft design proposals linked below. https://thunderbird.topicbox.com/groups/ux/Ta9a415d4e3e807cf/uxd-11-26-updates-mobile-message-list As you note, the app requires an account to be setup in order to access the settings. Without, they have little meaning. There would be no email to display the effect of font size, theming or color changes on. No server communication means notifications and other setting changes could not be tested. One idea might be to implement a limited pre-setup demo mode with a "welcome" email that users could test accessibility settings on. Mozilla connect is the best place to submit ideas and suggestions, which are then open to votes from the community. https://connect.mozilla.org/t5/ideas/idb-p/ideas/label-name/thunderbird%20android