How can I force the From: header (envelope sender) in PHP without putting it in mail()?

Question

I have a development web server (CentOS LAMP stack) that uses SMTP relays setup in postfix to send email. We use mailgun with multiple users, a setup similar to this, but with specific users instead of just wildcard emails:

/etc/postfix/main.cf

smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_auth_enable = yes
sender_dependent_relayhost_maps = hash:/etc/postfix/relayhost_map
smtp_sender_dependent_authentication = yes
smtp_sasl_security_options = noanonymous
relayhost = [smtp.mailgun.org]:587

/etc/postfix/sasl_passwd

# our domains
[email protected]  [email protected]:password1
[email protected]     [email protected]:password2
[email protected]  [email protected]:password3

# in-case we don't have it setup, use a default
#[smtp.mailgun.org]:587      [email protected]:password2

/etc/postfix/relayhost_map

[email protected]  [smtp.mailgun.org]:587
[email protected]     [smtp.mailgun.org]:587
[email protected]  [smtp.mailgun.org]:587

To setup email logging , I am authenticating each developer on the machine with their own SMTP credentials. I want to set it up so that developers don't need to add the additional_headers or additional_parameters to get the correct smtp relay match in postfix - and indeed it would take a lot of work to setup different mail headers in code for different developers, especially with versioned code. I digress. This was working fine from postfix's side of things when I use the following:

mail('[email protected]', 'subject', 'message here...', 'From: [email protected]', '[email protected]');

So I then added the following to the vhost configs:

php_admin_value sendmail_path "/usr/sbin/sendmail -t -i [email protected]"

which successfully allowed me to get rid of the -f additional_parameter and still send properly. Then I added the following:

php_value sendmail_from "[email protected]"

In a phpinfo() dump I see the local value for sendmail_from is set correctly, however now when I send the email it comes up as:

[email protected] on behalf of Apache

It seems as if the correct sender (MIME, not envelope, as postfix recognises the authentication and gives 250 Great success). With postfix logging on verbose, I see only references to the correct email from the sender input attribute.

In mailgun, I see the following information from the log, however, for the email when the From: [email protected] isn't used:

...
"envelope": {
    "transport": "smtp", 
    "sender": "[email protected]", 
    "sending-ip": "x.x.x.x", 
    "targets": "[email protected]"
}, 
"message": {
    "headers": {
        "to": "[email protected]", 
        "message-id": "[email protected]", 
        "from": "[email protected] (Apache)", 
        "subject": "Debug Test"
    }, 
    "attachments": [], 
    "recipients": [
        "[email protected]"
    ], 
    "size": 654
},
...

What's interesting is the same log for when From: [email protected] is present, the message->headers->from is set correcetly to [email protected] without the (Apache) addition. Surely this means that it's PHP's fault and that PHP is not utilising the sendmail_from value properly?

So with all this in mind, my resulting question is how can I set the default MIME Sender (From header) in PHP, apart from in the mail() function? Have I missed something with my method/config above, or is it just plain impossible? I'm happy to think outside the box a little, being that this will help save time for the reason we want this feature.

Answer 1

sendmail_from is ignored

From http://www.php.net/manual/en/mail.configuration.php:

sendmail_from string
Which "From:" mail address should be used in mail sent from PHP under Windows. This directive also sets the "Return-Path:" header.

So because you're using a CentOS LAMP stack, not Windows, this setting is ignored.

Also:

sendmail_path string
If set, smtp, smtp_port and sendmail_from are ignored and the specified command is executed.

So sendmail_from is also ignored because you're using sendmail_path.

Solution

You can also pass the -F (capital F) with an empty value to remove the "sender full name" from the header:

Pass -f [email protected] -F "" to the $additional_parameters argument of the mail() function.

Other notes

-f parameter

When you see your sender address changed, Postfix is doing that. This is because (in your case) the system-user under which Apache runs is calling the sendmail binary. And this binary will use <system-user>@<hostname> as sender address (unless told otherwise by the -f or -r parameter).

To prevent this, sendmail should be called with -f <sender address>. Either by passing it to the $additional_parameters argument of the mail() function, or by adding it to the sendmail_path ini-setting.

But it looks like you've already figured this out :)

A better solution

I suggest you don't use the ini-settings at all. In stead, write a small class around the mail() function:

class Mailer
{
    /**
     * @var string
     */
    private $fromEmail;

    /**
     * @var string
     */
    private $fromName;

    /**
     * @param string $fromEmail
     * @param string $fromName
     */
    public function __construct($fromEmail, $fromName)
    {
        $this->fromEmail = $fromEmail;
        $this->fromName  = $fromName;
    }

    /**
     * @param  string $to
     * @param  string $subject
     * @param  string $body
     * @param  array  $headers
     * @return bool
     */
    public function send($to, $subject, $body, array $headers = array())
    {
        $headers[]  = sprintf('From: "%s" <%s>', $this->fromName, $this->fromEmail);
        $parameters = sprintf('-f %s', $this->fromEmail);

        return mail($to, $subject, $body, $headers, $parameters);
    }
}

And use it like so:

$mailer = new Mailer('[email protected]', 'My Company');
$mailer->send('[email protected]', 'Subject', 'Body');

This class is over-simplified, but it should give you a basic idea of how negate the hassle of From: headers and -f parameters every time you want to send an e-mail.

And if you're using a Dependency Injection Container, or a Registry, you can configure/instantiate this class in the bootstrap phase of your application and simply grab it from the container/registry whenever you want to send an e-mail:

$container->get('mailer')->send($to, $subject, $message);

Or using a registry:

Registry::get('mailer')->send($to, $subject, $message);

3rd party library

In to long run it can be worth while to look into 3rd party libraries to send e-mails. I personally prefer Swift Mailer.