the Roundcube Webmail IMAP client: how to undelete messages

• https://en.wikipedia.org/wiki/Roundcube
• https://github.com/roundcube/roundcubemail/issues/1635
• https://github.com/roundcube/roundcubemail/issues/5133

It is not really obvious how to undelete messages with Roundcube. But it works:

• click on the icon!
• do not search for “Mark as undeleted“!