Setting SMTP responses for bouncing mail

Question

Goodday,

For a mailserver i have to read all bouncing mails that my mailserver sends. When a bounce occurs i recieve a response with sometimes a SMTP error response like 550 mailbox not found.

This is not always the case for bouncing emails sent by my own SMTP server, when for example the emailaddress is unroutable. I get a pretty non verbose response code and sometimes none at all.

Update

An example of a bouncing email:

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  ronancndjsnc@hotmail.com
    SMTP error from remote mail server after RCPT TO:<ronancndjsnc@hotmail.com>:
    host mx4.hotmail.com [65.55.33.135]: 550 Requested action not taken:
    mailbox unavailable


  ------ This is a copy of the message, including all the headers. ------

Another example:

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  ronanvbounce@myowndomain.com


------ This is a copy of the message, including all the headers. ------

As you can see the mail sent by myowndomain.com has a blank response. They both bounce because there is no mailbox found.

My question is: Is it possible for my mailserver at myowndomain.com to be more verbose when it comes to generating the response code for a bounce mail? And if so how do I set this with Exim or Postfix or any other SMTP software?

Can you please supply examples of bounced emails that you are having a problem with? — Ryan Babchishin, Oct 05 '15 at 08:05
Postfix gives more verbose messages (like hotmail does) by default. Have you tried it yet? I'm not familiar with Exim. — Ryan Babchishin, Oct 06 '15 at 10:02

Ryan Babchishin · Answer 1 · 2015-10-06T11:12:00.403

Try Postfix if you already haven't. It gives detailed bounce messages (like hotmail does) by default.

You can additionally configure Postfix to send custom bounce messages http://www.postfix.org/bounce.5.html

My postfix server's response to an invalid recipient:

This is the mail system at host mail.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

               The mail system

<fakeuser@mydomain.com>: unknown user: "fakeuser"

Very helpful @ryan-babchishin, i will definitely look in to this on the production server. Thanks. I will mark your answer as correct when i have a chance to look at this. — Rodracover, Oct 07 '15 at 12:57

Setting SMTP responses for bouncing mail

1 Answers1