We are using HubSpot for our normal campaign emails, but we also need to utilize its SMTP server to enable Auth0, which we use to manage our login process, the ability to send password reset and password change type of emails. While I can create a test mail client and successfully send a mail through smtp.hubapi.com, the exact same credentials fail when I try to send a test email using Auth0. The only error codes I get are:
“error”: “Invalid login sequence while waiting for “334 VXNlcm5hbWU6”: 334 VXNlcm5hbWU6 R6n7Dck9nW4w1nb83nMhVR0 - hssmtp”
I also have Auth0 looking at this issue. However, I can also get a test email to work from Auth0 to a test SMTP server at smtp.gmail.com, so the issue isn’t completely on Auth0’s side. What could be causing the incompatibility here?