This incident has been resolved, Sendgrid confirmed the resolution. You can receive e-mails from Tresorit now.
Posted Dec 05, 2019 - 14:02 UTC
Tresorit customers cannot receive emails for 2-factor authentication when logging in and freshly created Tresorit users cannot verify their email address because of a lack of verification email due to our 3rd party email provider, Sendgrid issues. This email service is not available from 10:30 CET. Sendgrid is already working on the solution.