Mandrill "reject_reason": "invalid-sender"

S M Azam picture S M Azam · Dec 16, 2013 · Viewed 16.1k times · Source

I'm trying to send emails using mandrill email service but I get the following error

    Full Response
[
    {
        "email": "[email protected]",
        "status": "rejected",
        "_id": "b814c2974594466cba9c904c54dca6c6",
        "reject_reason": "invalid-sender"
    }
]

Apart from the above error there is no more details about it. we are using .net to send emails with Mandrill SMTP settings.

Answer

Kaitlin picture Kaitlin · Dec 16, 2013

It'd be useful to see the call/email that's being sent. That error means that there's an invalid sender, as indicated in the reject reason field. That could be because of an invalid email address, invalidly-encoded from name, or invalid or broken encoding in other headers making it so that Mandrill can't parse the "from" header, but without seeing the actual email that you're sending, it's hard to say for sure exactly what the issue is.

You probably want to check that there's a fully-qualified domain name in the from email address, and that if the subject line is encoded, there aren't things like newline (\n) characters that break multibyte characters in the subject line. If you aren't able to identify the issue in the raw SMTP message, feel free to get in touch with support for further troubleshooting assistance.