String to be inserted at the end of the email header.
This is typically used to add extra headers (From, Cc, and Bcc).
Multiple extra headers should be separated with a CRLF (\r\n).
When sending mail, the mail must contain
a From header. This can be set with the
additional_headers parameter, or a default
can be set in php.ini.
Failing to do this will result in an error
message similar to Warning: mail(): "sendmail_from" not
set in php.ini or custom "From:" header missing.
If messages are not received, try using a LF (\n) only.
Some poor quality Unix mail transfer agents replace LF by CRLF
automatically (which leads to doubling CR if CRLF is used).
This should be a last resort, as it does not comply with
The additional_parameters parameter
can be used to pass an additional parameter to the program configured
to use when sending mail using the sendmail_path
configuration setting. For example, this can be used to set the
envelope sender address when using sendmail with the
-f sendmail option.
The user that the webserver runs as should be added as a trusted user to the
sendmail configuration to prevent a 'X-Warning' header from being added
to the message when the envelope sender (-f) is set using this method.
For sendmail users, this file is /etc/mail/trusted-users.
Returns TRUE if the mail was successfully accepted for delivery, FALSE otherwise.
It is important to note that just because the mail was accepted for delivery,
it does NOT mean the mail will actually reach the intended destination.
4.3.0 (Windows only)
All custom headers (like From, Cc, Bcc and Date) are supported, and are
(As custom headers are not interpreted by the MTA in the first place,
but are parsed by PHP, PHP < 4.3 only supported the Cc header element
and was case-sensitive).
The additional_parameters parameter is disabled in
safe_mode and the
mail() function will expose a warning message
and return FALSE when used.
The additional_parameters parameter was added.
Example 1. Sending mail.
Using mail() to send a simple email:
<?php // The message $message = "Line 1\nLine 2\nLine 3";
// In case any of our lines are larger than 70 characters, we should use wordwrap() $message = wordwrap($message, 70);
// Mail it mail($to, $subject, $message, $headers); ?>
If intending to send HTML or otherwise Complex mails, it is recommended
to use the PEAR package PEAR::Mail.
The Windows implementation of mail() differs in many
ways from the Unix implementation. First, it doesn't use a local binary
for composing messages but only operates on direct sockets which means a
MTA is needed listening on a network socket (which
can either on the localhost or a remote machine).
Second, the custom headers like
not interpreted by the
MTA in the first place, but are parsed by PHP.
As such, the to parameter should not be an address
in the form of "Something <firstname.lastname@example.org>". The
mail command may not parse this properly while talking with
Email with attachments and special
types of content (e.g. HTML) can be sent using this function. This is
accomplished via MIME-encoding - for more information, see this
Zend article or the
PEAR Mime Classes.
It is worth noting that the mail() function is not
suitable for larger volumes of email in a loop. This function opens
and closes an SMTP socket for each email, which is not very efficient.