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.
When sending an email, *Claws Mail* copies the email in plaintext to the sending queue of the IMAP server before encrypting the email.*Claws Mail* deletes this plaintext copy after sending the email.
Automatically if you selected the **automatically save message to Draft folder** option in the writing preferences. This option is deselected by default in Tails.
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.