When a user has less than 10% of free storage space, show a warning message like "your inbox is almost full". When a user has less than 1% left, show a message like "your inbox is full". Of course, the latter is just a heuristic, but this should be good enough in most cases.

Based on #1, we can release another breaking-change version. The goal: In the end, b1gmail should focus on email. Not on features like calendar, tasks, and the like. Thus, we want to remove features that are not related to emailing. Also, we want to remove features that are hard to maintain or don't really serve a purpose in the (near) future of this project.

• Remove the Calendar
• Remove the Tasks feature
• Remove the Notes feature
• Remove the Webdisk
• Remove the pop3 collection feature (we are currently storing passwords in cleartext in the database for this!)
• Remove email encryption features?
• Remove Widgets
• Remove the start page and, by default, show the email inbox
• Remove the Toolbox
• Remove the notification feature (i.e. the menu you can see on the right top in the LI area)
• Remove the "new" menu (i.e. the menu next to the notification bell)
• Remove the interface/ folder (1)
• Remove Workgroups

(1) We have not removed the entire interface/ folder because the pipe feature might become useful in the future. However, we have removed all other parts of this folder.

Things that still need to be done/checked/clarified:

• We probably don't want public signup features. Should we remove them in this release already? If so, then there are quite a lot of additional things we can remove
  • The features for account abuse detection
  • Payment features
  • Coupons
  • Captchas in general (but only do this if we also decide to remove the public contact form)
  • The ZIP check feature
• The country list feature. The countries are all listed in a database table, and the names are hardcoded in German.
• Remove SMS features
• Remove the Webdisk Icons feature from the admin area
• Remove the plugin update and installation features from the admin area
• Remove the "help" feature from the admin area
• Remove the language upload feature from the admin area, and stop requiring write permissions on these files
• Move language files into serverlib/?
• Add a warning if the setup folder has not been deleted (Update: Added a tool to automatically delete this folder and other folders)

I don't see any valid reason why we need the X-Sender-IP and X-Mailer header fields. On the contrary, I believe that they could lead to privacy-related issues.

Admins can disable the X-Sender-IP header using the Admin UI. Thus, we don't need to change anything immediately.