Bad username / password

Hi
I constantly get “Bad username / password” when sending or testing from mailpoet. I set in mailpoet the same credentials as in sendgrid (login: “trubinsendgrid”, pwd “True#37sendgrid”,sending with “true.photo@trueprojekte.com” to the test adress “th-rubin@bluewin.ch”
Using W 10 64 bit, mailpoet 4.7.5
Thanks for help