Mailspring breaks hyperlinks of proofpoint urldefense urls


Many listervs use urldefense to create hyperlinks in emails by appending “" to before the url and ";!!” followed by a series of numbers and letters to the end of the url. Mailspring seems to disrupt these hyperlinks at the “http://” of the inner url so you cannot click the hyperlink, but instead have to highlight the whole line and copy and it into your browser. Occasionally, no hyperlink is generated and the entire url is just printed in plain text. I have examples of both of these in the screenshot below.

To reproduce, subscribe to any listserv that uses proofpoint urldefense and observe any links included in listserv emails. This seems to be becoming standard at universities and other organizations.

The expected behavior is to create a hyperlink for the whole urldefense url starting from the “” prefix to the inner url to the “__;!!..” suffix. This is how it works in the web browser email clients that I have tried (Gmail, Webmail).



  • OS and Version: Ubuntu 18.04.5 LTS
  • Mailspring Version: 1.7.8

(Originally posted by amorris28 on GitHub.)