Strapi is not sending all emails

System Information
  • Strapi Version: 3.6.2
  • Operating System: Linux
  • Database: postgres
  • Node Version: 14.19.1
  • NPM Version: 6.14.16
  • Yarn Version: 1…2.5

I’m using nodemailer as a provider to send emails through SendGrid.

When I’m testing on Settings > Email Plugin - Email Settings > Send a test email all messages are sent as expected.

When I test on the forgot-password flow, using the same email addresses on the test above, not all emails are sent. Gmail addresses received both messages, Microsoft (Hotmail/Live) and domains using Exchange email server don’t receive the forgot-password message.

If we are talking about some block, blacklist, firewall, or rule… it doesn’t make sense because the test email always worked.

Things that I tried to solve this with no success:

  • add dkim certificate to nodemailer
  • domain and sender are verified on SendGrid
  • SMTP connection using the same sender email
  • forgot-password email template (subject and content) override.
  • tested all other providers (Sendmail, SendGrid, SMTP)
  • rule added on Exchange to ensure that emails coming from my Strapi server will be allowed.

I don’t know what else I can try to resolve this. Does anyone have any ideas?

Thank you!