运行时配置

这些函数的行为受 php.ini 中的设置影响。

Mail 配置选项
名字 默认 可修改范围 更新日志
mail.add_x_header "0" PHP_INI_PERDIR 自 PHP 5.3.0 起生效
mail.log NULL PHP_INI_PERDIR 自 PHP 5.3.0 起生效
SMTP "localhost" PHP_INI_ALL  
smtp_port "25" PHP_INI_ALL 自 PHP 4.3.0 起可用
sendmail_from NULL PHP_INI_ALL  
sendmail_path NULL PHP_INI_SYSTEM  
有关 PHP_INI_* 样式的更多详情与定义，见 配置可被设定范围。

这是配置指令的简短说明。

mail.add_x_header bool

Add X-PHP-Originating-Script that will include UID of the script followed by the filename.

mail.log string

The path to a log file that will log all mail() calls. Log entries include the full path of the script, line number, To address and headers.

SMTP string

仅用于 Windows：PHP 在 mail() 函数中用来发送邮件的 SMTP 服务器的主机名称或者 IP 地址。

smtp_port int

仅用于 Windows：SMTP 服务器的端口号，默认为 25。自 PHP 4.3.0 起可用。

sendmail_from string

在 Windows 下用 PHP 发送邮件时的"From:"邮件地址的值。该选项同时设置了 "Return-Path:"头。

sendmail_path string

sendmail 程序的路径，通常为 /usr/sbin/sendmail 或 /usr/lib/sendmail。configure 脚本会尝试找到该程序并设定为默认值，但是如果失败的话，可以在这里设定。

不使用 sendmail 的系统应将此指令设定为其邮件系统提供的 sendmail 替代程序，如果有的话。例如，» Qmail 用户通常可以设为 /var/qmail/bin/sendmail 或 /var/qmail/bin/qmail-inject。

qmail-inject 不需要任何选项就能正确处理邮件。

此指令也可用于 Windows。如果设定，smtp，smtp_port 和 sendmail_from 都被忽略并运行指定的命令。

User Contributed Notes

php dot net at ii0 dot net 17-Nov-2016 05:46
If anyone gets this cryptic error message in the PHP error logs:
"sh: -t: command not found"
after upgrading from PHP 5.4, this may be the solution for you.

I upgraded PHP from 5.4 to 5.6 and all our mail() functionality suddenly broke, with no useful error logging.

If this is you, and you've been using ini_set() to set the "sendmail_path" then note that even though it's apparently not mentioned in the upgrade documentation -- or anywhere else I could find on php.net (or a dozen forums) -- you'll now need to go set the sendmail_path in your php.ini file; it is now ignored if you use ini_set() to specify a path to the sendmail binary on the fly.

So, just specify "sendmail_path" in php.ini instead.  That's all there is to it -- that fixed all the mail() functionality for us. 

Hope this little note saves someone else as much time as I spent troubleshooting and researching.  Cheers!
phpnote-mail at revmaps dot no-ip dot org 20-Jan-2016 06:16
setting return path:

 Return-path header does not work because it is not part of smtp.

 on *nix -f may be set on the mail command
alternatively
 some MTAs accept mbox-style "From " header on the first header line
note: no colon after "From" , must be the first header line
or  you may be able to re-configure you MTA to interpret return-path headers

 -f is the most reliable method but it may mean that you can't set any other command-line option due to shell escaping problems.

also note that email formatting requirements differ between windows and everything else. sendmail expects only \n line-endings
elitescripts2000 at yahoo dot com 09-Dec-2013 04:52
On Ubuntu 13.04, not sure of the other Distros.

If you simply uncomment the default:

sendmail_path = "sendmail -t -i"

Your mail() functions will all fail.  This is because, you should place the FULL PATH (i.e.  /usr/sbin/sendmail -t -i )

The documentation states PHP tries it's best to find the correct sendmail path, but it clearly failed for me.

So, always enter in the FULLPATH to sendmail or you may get unexpected failing results.

As a secondary note:  Those that just want to ENFORCE the -f parameter, you can do so in php.ini using:

mail.force_extra_parameters = -fdo_not_reply@domain.tld

You can leave the sendmail path commented out, it will still use the defaults  (under UNIX  -t -i options which if you look them up are very important to have set)....

But, now there is no way to change this, even with the 5th argument of the mail() function.  -f is important, because if NOT set, will be set to which ever user the PHP script is running under, and you may not want that.

Also, -f  sets the Return-Path:  header which is used as the Bounce address, if errors occur, so you can process them.  You you can not set Return-Path: in mail() headers for some reason... you could before.  Now you have to use the -f option.
mike dot castrodemaria at gmail dot com 20-Jun-2013 11:00
You can set on apache2 a "per domain" default address in apache conf VirtualHost section too.

Juste add : php_admin_value sendmail_path "/usr/sbin/sendmail -t -i -fno-reply@php.net -Fno-reply"

change to your own email choice instead no-reply@php.net .

I hope this helps,
Mike
blueshibuyadream at gmail dot com 28-Mar-2013 09:27
On Darwin OS such as OSX (current one: 10.8.3) you need to add a specific command and option to the sendmail_path constant if you have downloaded and installed a mamp with a stack.

Indeed you can see the required libraries for PHP, Apache, MySQL in "common/lib" folder. The problem is when you run an external command using these libraries, for example "sendmail". It could be a problem if it gets the stack libraries and not the system ones (different versions, etc).

The "env -i" command clean the Stack environment variables and run "sendmail" with the system libraries.

Hope this helps.
rgdobie at conwave dot com dot au 22-Feb-2013 03:46
Under Windows, I found sendmail_from needed to be a valid email address which has been defined on the mail server being addressed.
A Austin 12-Jul-2012 02:40
For linux you can over-ride the default "From" for the outgoing emails by including in php.ini this line:

sendmail_path = "/usr/sbin/sendmail -t -i -f fromMe@blah.com"

The path should work for most linux installations.
Robert 25-Apr-2011 08:09
Despite what this page says about the "SMTP" and "smtp_port" settings being used only under Windows, all Drupal sites use these settings to send email, regardless of which OS they're running in.