Hotmail is ignoring return-path header

Question

I am using this php class on a small email list manager, I am using a hotmail email and smtp.live.com to send the emails. It works fine, but I am getting some bounced emails so I wanted to receive them on a different address where it would be easier for me to manage them. I have tried using the Return-Path header but hotmail seems to ignore it and still send the bounces to the "from" address. I also noticed that the class sends "NOTIFY=NEVER ORCPT=rfc822" to "disable" dsn but hotmail also seems to ignore it.

The SMTP transaction printed by the php class looks something like this:

Resolving SMTP server domain "smtp.live.com"...
Connecting to host address "65.55.96.11" port 587...
Connected to SMTP server "smtp.live.com".
S 220 BLU0-SMTP333.blu0.hotmail.com Microsoft ESMTP MAIL Service, Version: 6.0.3790.4675 ready at Sat, 20 Oct 2012 06:51:46 -0700
C EHLO 192.168.1.1
S 250-BLU0-SMTP333.blu0.hotmail.com Hello [1.2.3.4]
S 250-TURN
S 250-SIZE 44242340
S 250-ETRN
S 250-PIPELINING
S 250-DSN
S 250-ENHANCEDSTATUSCODES
S 250-8bitmime
S 250-BINARYMIME
S 250-CHUNKING
S 250-VRFY
S 250-TLS
S 250-STARTTLS
S 250 OK
C STARTTLS
S 220 2.0.0 SMTP server ready
Starting TLS cryptograpic protocol
TLS started
C EHLO 192.168.1.1
S 250-BLU0-SMTP366.blu0.hotmail.com Hello [1.2.3.4]
S 250-TURN
S 250-SIZE 44242340
S 250-ETRN
S 250-PIPELINING
S 250-DSN
S 250-ENHANCEDSTATUSCODES
S 250-8bitmime
S 250-BINARYMIME
S 250-CHUNKING
S 250-VRFY
S 250-AUTH LOGIN PLAIN
S 250 OK
C AUTH LOGIN
S 334 DXdlcm3hfW36
C ZW1haWwxQGhvdG1haWwuY29t
S 334 UDCzd5dvdmQe
C MTIzNDU2
S 235 2.7.0 Authentication succeeded
C MAIL FROM:<[email protected]>
C RCPT TO:<[email protected]> NOTIFY=NEVER ORCPT=rfc822;email-that-bounces
C DATA
S 250 2.1.0 [email protected] OK
S 250 2.1.5 [email protected]
S 354 Start mail input; end with <CRLF>.<CRLF>
C From: [email protected]
To: [email protected]
Return-Path: <[email protected]>
Content-Type: multipart/alternative; boundary="fd9c131c7e7f727fd34567b8a131218a52114gha"
Subject: subject
Date: Sat, 20 Oct 2012 15:51:45 CEST
MIME-Version: 1.0


C --fd9c131c7e7f727fd34567b8a131218a52114gha
Content-Type: text/plain; charset="ISO-8859-1
Content-Transfer-Encoding: 7bit

email message

--fd9c131c7e7f727fd34567b8a131218a52114gha
Content-Type: text/html; charset="ISO-8859-1"
Content-Transfer-Encoding: 7bit

email message

--aa9c111c7e7f727bf74367b8a131918a36314dba--
C
.
S 250 2.6.0 <[email protected]> Queued mail for delivery
C QUIT
S 221 2.0.0 BLU0-SMTP333.blu0.hotmail.com Service closing transmission channel
Disconnected.

This is how i send the email:

$smtp->SendMessage(
    $from, array( $to ),

    array(
        "From: $from",
        "To: $to",
        "Return-Path: <[email protected]>",
        'Content-Type: multipart/alternative;   boundary="'.$boundary.'"',
        "Subject: $subject",
        "Date: ".strftime("%a, %d %b %Y %H:%M:%S %Z"),
        "MIME-Version: 1.0"
), "$body");

If I log into hotmail and check the "sent" folder, the email sent doesn't contain the return path header.

Is there something wrong with the headers I send or hotmail just don't support return-path

Answer 1

The Return-Path is actually not part of the e-mail, it is part of the SMTP envelope. What this means is that you cannot add it as any other mail header.

Return-Path is instead derived from the SMTP transaction. More specifically, this is where the Return-Path is set:

MAIL FROM:<[email protected]>

Answer 2

I see that you are not using \r\n as end of line in your code. Your should try to add it and recheck. Lots of reports and strange behaviours are reported due to the lack of those characters

Hotmail do support return-path, a few times I have forgotten that header and the test mails ended up in the junk folder, and as soon as I added it, the messages went straight to the inbox