I have a mystery that I would appreciate some help to understand.
So a business partner was trying to send me an email with two hyperlinks. But their corporate email server kept returning the message, "Your message to my_corporate_email has been blocked. See technical details below for more information."
550 permanent failure for one or more recipients (my_corporate_email:blocked)
It wasn't just my email but others in my organisation could also not receive this email with the two hyperlinks. I then got hold of the email's content by having them send it to my personal Gmail account. I tried to send it to my corporate email from my Gmail but I got the same error message.
After experimenting, I determine that one of the hyperlinks was causing the rejection. But I don't understand why as the link was just to another corporation's web page. I don't see why it would be blocked by our mail servers. Also, I checked the blocklist and it wasn't on it.
Does anyone have any ideas about what could be happening? For what it's worth, our corporation runs Microsoft Exchange servers.
Your organization's Exchange server most likely uses some software that filters and blocks mails that have malicious or suspicious links in them, that is the reason for you not receiving the email.