We discovered that *Claws Mail*, the email client in Tails, stores plaintext copies of all emails on the remote IMAP server, including those that are meant to be encrypted.
Unfortunately, we were not yet able to fix the problem automatically and for everybody. This would require to either modify *Claws Mail* or to migrate to a different application. Refer to the workarounds section to solve this problem in your setup and please warn others around you.
First of all, verify the content of the **Drafts** folder on the server, either through *Claws Mail* or through the web interface of your email provider. Delete any plaintext email that might have been stored against your will in this folder until now.
With IMAP, *Claws Mail* constantly synchronizes with the server and displays the emails and folders that are currently stored on the server. IMAP is better suited if you access your emails from different operating systems.
With POP, *Claws Mail* downloads the emails that are in the inbox on the server and possibly removes them from the server. POP is better suited if you access emails from Tails only and store them in the persistent volume.
To know more, see also this Yahoo! Help page on [comparing the differences between POP and IMAP](https://help.yahoo.com/kb/mail-for-desktop/compare-differences-pop-imap-sln3769.html).