sendmail和php mail（） - “找不到收件人”

I have installed sendmail on my Apache server (Ubuntu)

Everything seems to work find except an email is not beeing sent while using php mail();

I get an error on the Apache errorlog saying:

/usr/sbin/sendmail: no recipients found

This is the way I'm using the function:

$user_email = "myemail@gmail.com";
$headers  = 'MIME-Version: 1.0' . "
";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "
";
$headers .= 'To: ' . $user_email . "
";
$headers .= 'From: Mydomain <do-not-reply@mydomain.com>' . "
";

  mail($user_email,"subject","message",$headers);

$user_email = myemail@gmail.com

should be

$user_email = "myemail@gmail.com";

What caused the error is that you had (in your original posted code):

$user_email = myemail@gmail.com

Both encompassing quotation marks and ending semi-colon were not present.

Here is the correct and proper form:

$user_email = "myemail@gmail.com";

It can also be written like this, using single quotes:

$user_email = 'myemail@gmail.com';

As taken from the mail() function on PHP.net

http://php.net/manual/en/function.mail.php

I installed ssmtp on my ubuntu/apache2/php set up, and I found I had to set the sendmail parameters in php.ini

mail.force_extra_parameters = -t

As I understand it, ssmtp emulates a sendmail set up, and the -t parameter forces the mta to scan the incoming mail (from PHP) for a 'To:' header.

As a point of note, I also had to change the symbolic link that the ssmtp install created to include the full path of the bin (ln -s /usr/sbin/ssmtp sendmail), so that the file could be found by apache