如何使用php代码发送电子邮件？

我试图从codeigniter项目中发送一封电子邮件，命令

echo$this->email->print_debugger（）继续返回以下内容：

220 smtp.gmail.com ESMTP q139sm4099547wmd.2-gsmtp

您好：250-smtp.gmail.com，随时为您服务，[41.228.226.174]
250号35882577
250-8比特
250-STARTTLS
250-增强状态码
250-流水线
250 SMTPUTF8
无法发送AUTH LOGIN命令。错误：530 5.7.0必须
首先发出STARTTLS命令。q139sm4099547wmd.2-gsmtp无法
使用PHP SMTP发送电子邮件。您的服务器可能未配置为发送
使用此方法发送邮件

所以我回去尝试用没有codeigniter的简单php代码发送电子邮件，结果发现最初的问题与codeingiter无关，因为我再次失败。
以下是我的php代码：

<?php
$to       = '**********@gmail.com';
$subject  = 'Testing sendmail.exe';
$message  = 'Hi, you just received an email using sendmail!';
$headers  = 'From: ******@gmail.com' . "\r\n" .
            'MIME-Version: 1.0' . "\r\n" .
            'Content-type: text/html; charset=utf-8';
if(mail($to, $subject, $message, $headers))
    echo "Email sent";
else
    echo "Email sending failed";
?>

我还尝试删除行
sendmail\u path=………

最后是我的sendmail.ini：

; configuration for fake sendmail

; if this file doesn't exist, sendmail.exe will look for the settings in
; the registry, under HKLM\Software\Sendmail

[sendmail]

; you must change mail.mydomain.com to your smtp server,
; or to IIS's "pickup" directory.  (generally C:\Inetpub\mailroot\Pickup)
; emails delivered via IIS's pickup directory cause sendmail to
; run quicker, but you won't get error messages back to the calling
; application.

smtp_server=smtp.gmail.com

; smtp port (normally 25)

smtp_port=25

; SMTPS (SSL) support
;   auto = use SSL for port 465, otherwise try to use TLS
;   ssl  = alway use SSL
;   tls  = always use TLS
;   none = never try to use SSL

smtp_ssl=

; the default domain for this server will be read from the registry
; this will be appended to email addresses when one isn't provided
; if you want to override the value in the registry, uncomment and modify

default_domain=

; log smtp errors to error.log (defaults to same directory as sendmail.exe)
; uncomment to enable logging

error_logfile=error.log

; create debug log as debug.log (defaults to same directory as sendmail.exe)
; uncomment to enable debugging

debug_logfile=debug.log

; if your smtp server requires authentication, modify the following two lines

auth_username=***********@gmail.com
auth_password=*******************

; if your smtp server uses pop3 before smtp authentication, modify the 
; following three lines.  do not enable unless it is required.

pop3_server=
pop3_username=
pop3_password=

; force the sender to always be the following email address
; this will only affect the "MAIL FROM" command, it won't modify 
; the "From: " header of the message content

force_sender=************@gmail.com

; force the sender to always be the following email address
; this will only affect the "RCTP TO" command, it won't modify 
; the "To: " header of the message content

force_recipient=

; sendmail will use your hostname and your default_domain in the ehlo/helo
; smtp greeting.  you can manually set the ehlo/helo name if required

hostname=localhost

任何帮助都将不胜感激，因为我已经花了3天多的时间试图解决这个问题，但都无济于事

编辑：第二个代码确实返回“Email sent”，但我在任何地方都找不到它，甚至在垃圾邮件中也找不到。是的，我已将gmail配置为“允许不太安全的应用程序”
您的电子邮件发送部分是正确的。没问题

如果您通过电子邮件发送邮件，则必须正确配置电子邮件设置

如果XAMPP
如果Wamp
注意：如果您有live server，请将其上载到live。它比配置本地设置和所有设置更容易检查

您的电子邮件代码是可以的，但如果您使用的是wamp服务器…需要更改以下内容

访问您的电子邮件帐户。单击齿轮工具>设置>
转发和POP/IMAP>IMAP访问。单击“启用IMAP”，然后单击
保存您的更改
运行WAMP服务器。在Apache模块下启用ssl_模块
接下来，在php下启用php_openssl和php_套接字
**在
“C:\wamp\bin\php\php5.5.12\php.ini”
和
“C:\wamp\bin\apache\apache2.4.9\bin\php.ini”
**
sendmail\u path=“C:\wamp\sendmail\sendmail.exe-t”

重新启动Wamp服务器
我想它会成功的。
在config/email.php中，我必须添加

$config['smtp_crypto']=“tls”
 在本地或live server中，恐怕这并不能解决问题将其加载到live server
; configuration for fake sendmail

; if this file doesn't exist, sendmail.exe will look for the settings in
; the registry, under HKLM\Software\Sendmail

[sendmail]

; you must change mail.mydomain.com to your smtp server,
; or to IIS's "pickup" directory.  (generally C:\Inetpub\mailroot\Pickup)
; emails delivered via IIS's pickup directory cause sendmail to
; run quicker, but you won't get error messages back to the calling
; application.

smtp_server=smtp.gmail.com

; smtp port (normally 25)

smtp_port=25

; SMTPS (SSL) support
;   auto = use SSL for port 465, otherwise try to use TLS
;   ssl  = alway use SSL
;   tls  = always use TLS
;   none = never try to use SSL

smtp_ssl=

; the default domain for this server will be read from the registry
; this will be appended to email addresses when one isn't provided
; if you want to override the value in the registry, uncomment and modify

default_domain=

; log smtp errors to error.log (defaults to same directory as sendmail.exe)
; uncomment to enable logging

error_logfile=error.log

; create debug log as debug.log (defaults to same directory as sendmail.exe)
; uncomment to enable debugging

debug_logfile=debug.log

; if your smtp server requires authentication, modify the following two lines

auth_username=***********@gmail.com
auth_password=*******************

; if your smtp server uses pop3 before smtp authentication, modify the 
; following three lines.  do not enable unless it is required.

pop3_server=
pop3_username=
pop3_password=

; force the sender to always be the following email address
; this will only affect the "MAIL FROM" command, it won't modify 
; the "From: " header of the message content

force_sender=************@gmail.com

; force the sender to always be the following email address
; this will only affect the "RCTP TO" command, it won't modify 
; the "To: " header of the message content

force_recipient=

; sendmail will use your hostname and your default_domain in the ehlo/helo
; smtp greeting.  you can manually set the ehlo/helo name if required

hostname=localhost