GoLang mail

request it (343)
GoLang replacement for PHP's mail [edit | history]

Do you know a GoLang replacement for PHP's mail? Write it!

PHP mail

PHP original manual for mail [ show | php.net ]


(PHP 4, PHP 5, PHP 7)

mailSend mail


bool mail ( string $to , string $subject , string $message [, mixed $additional_headers [, string $additional_parameters ]] )

Sends an email.



Receiver, or receivers of the mail.

The formatting of this string must comply with » RFC 2822. Some examples are:


Subject of the email to be sent.


Subject must satisfy » RFC 2047.


Message to be sent.

Each line should be separated with a CRLF (\r\n). Lines should not be larger than 70 characters.


(Windows only) When PHP is talking to a SMTP server directly, if a full stop is found on the start of a line, it is removed. To counter-act this, replace these occurrences with a double dot.


additional_headers (optional)

String or array 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). If outside data are used to compose this header, the data should be sanitized so that no unwanted headers could be injected.

If an array is passed, its keys are the header names and its values are the respective header values.


Before PHP 5.4.42 and 5.5.27, repectively, additional_headers did not have mail header injection protection. Therefore, users must make sure specified headers are safe and contains headers only. i.e. Never start mail body by putting multiple newlines.


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. The From header sets also Return-Path under Windows.


If messages are not received, try using a LF (\n) only. Some Unix mail transfer agents (most notably » qmail) 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 » RFC 2822.

additional_parameters (optional)

The additional_parameters parameter can be used to pass additional flags as command line options to the program configured to be used when sending mail, as defined by 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.

This parameter is escaped by escapeshellcmd() internally to prevent command execution. escapeshellcmd() prevents command execution, but allows to add additional parameters. For security reasons, it is recommended for the user to sanitize this parameter to avoid adding unwanted parameters to the shell command.

Since escapeshellcmd() is applied automatically, some characters that are allowed as email addresses by internet RFCs cannot be used. mail() can not allow such characters, so in programs where the use of such characters is required, alternative means of sending emails (such as using a framework or a library) is recommended.

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.

Return Values

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.


Version Description
7.2.0 The additional_headers parameter now also accepts an array.
5.4.42, 5.5.27 Header injection protection has been addded for the additional_headers parameter. This means that multiple consecutive newlines are no longer allowed.
4.2.3 The additional_parameters parameter is disabled in safe_mode and the mail() function will expose a warning message and return FALSE when used.


Example #1 Sending mail.

Using mail() to send a simple email:

// The message
$message "Line 1\r\nLine 2\r\nLine 3";

// In case any of our lines are larger than 70 characters, we should use wordwrap()
$message wordwrap($message70"\r\n");

// Send
mail('[email protected]''My Subject'$message);

Example #2 Sending mail with extra headers.

The addition of basic headers, telling the MUA the From and Reply-To addresses:

'[email protected]';
$subject 'the subject';
$message 'hello';
$headers 'From: [email protected]"\r\n" .
'Reply-To: [email protected]"\r\n" .
'X-Mailer: PHP/' phpversion();


Example #3 Sending mail with extra headers as array

This example sends the same mail as the example immediately above, but passes the additional headers as array (available as of PHP 7.2.0).

'[email protected]';
$subject 'the subject';
$message 'hello';
$headers = array(
'From' => '[email protected]',
'Reply-To' => '[email protected]'
=> 'PHP/' phpversion()


Example #4 Sending mail with an additional command line parameter.

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.

('[email protected]''the subject''the message'null,
'[email protected]');

Example #5 Sending HTML email

It is also possible to send HTML email with mail().

// Multiple recipients
$to '[email protected][email protected]'// note the comma

// Subject
$subject 'Birthday Reminders for August';

// Message
$message '
  <title>Birthday Reminders for August</title>
  <p>Here are the birthdays upcoming in August!</p>

// To send HTML mail, the Content-type header must be set
$headers[] = 'MIME-Version: 1.0';
$headers[] = 'Content-type: text/html; charset=iso-8859-1';

// Additional headers
$headers[] = 'To: Mary <[email protected]>, Kelly <[email protected]>';
$headers[] = 'From: Birthday Reminder <[email protected]>';
$headers[] = 'Cc: [email protected]';
$headers[] = 'Bcc: [email protected]';

// Mail it


If intending to send HTML or otherwise Complex mails, it is recommended to use the PEAR package » PEAR::Mail_Mime.



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 From:, Cc:, Bcc: and Date: are 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 <[email protected]>". The mail command may not parse this properly while talking with the MTA.


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.

For the sending of large amounts of email, see the » PEAR::Mail, and » PEAR::Mail_Queue packages.


The following RFCs may be useful: » RFC 1896, » RFC 2045, » RFC 2046, » RFC 2047, » RFC 2048, » RFC 2049, and » RFC 2822.

See Also