after using arduino.app -> impossible to send mail with mail.app

after using the arduino.app on osx, it will block the outgoing mail from being send. only rebooting osx will make send emails through mail.app possible again.

this was also happening in previous versions e.g. 1.8.1

any hints as how to solve this?

is the arduino.app using some native libraries to access web pages and as a side-effect mixing cookies that will prevent osx mail.app from sending mail over smtp ?