Email Troubleshooting

I used this article:

and I tried everything they suggested, the syntax is correct, my SMTP connections are not blocked, there are no errors or anything related to mail in the Discourse logs, there are no errors in Mailjet’s (my email provider) logs, I properly set up DKIM and SPF records, the email domain is correct, I am not using an IP address as the domain, I’ve changed the port and tried all the possible options, none seem to fix it.

The last thing which I haven’t done is,

But I want to see if there is anything else I can do as if I choose the above method, I’ll have a broken email which is something I don’t want. Anyone got any fixes?

The forum I’m using:

Is anyone able to help?