roundcube plugin: DKIM verification status
DKIMSTATUS displays the status of the DKIM Signature of each email you read in Roundcube. It does not carry out its own DKIM checks; it only reports information added to headers by an MTA or spam filter. Warning: this plugin is unmaintained upstream and may be removed in the future.
Homepage: https://jve.linuxwall.info/blog/index.php?pages/DKIMSTATUS-plugin-for-roundcube