如何使用带有自定义域 (https) 的 Sendgrid 和 Google App Engine 发送电子邮件

Question

I'm have a web app hosted on Google App Engine written in Codeigniter (PHP). I use sendgrid to send transactional emails.

The app was initially hosted on https://appid.appspot.com and the everything was fine.

I recently changed the app URL to https://app.domain.com and imported a SSL certificate that I purchased from godaddy. As far as the ssl certificate is concerned I do not have any issue.

However while sending transactional email I get the following error.

Severity: Warning

Message: fsockopen(): php_network_getaddresses: gethostbyname failed. errno=0

Filename: libraries/Email.php

Line Number: 1949

Backtrace:

File: /base/data/home/apps/s~chutti-app-prod/1.388253899009796980/application/controllers/Signup.php
Line: 60
Function: send

File: /base/data/home/apps/s~chutti-app-prod/1.388253899009796980/index.php
Line: 292
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: fsockopen(): unable to connect to smtp.sendgrid.net:587 (php_network_getaddresses: gethostbyname failed. errno=0)

Filename: libraries/Email.php

Line Number: 1949

Backtrace:

File: /base/data/home/apps/s~chutti-app-prod/1.388254166863409817/application/controllers/Signup.php
Line: 60
Function: send

File: /base/data/home/apps/s~chutti-app-prod/1.388254166863409817/index.php
Line: 292
Function: require_once

The sendgrid credentials are same as I used the same credentials in a different application hosted at https://app.appspot.com and everything is fine. The problem is only with my custom URL with https.

Code that sends email

$this->load->library('email');

$this->email->initialize(array(
              'protocol' => 'smtp',
              'smtp_host' => 'smtp.sendgrid.net',
              'smtp_user' => 'username',
              'smtp_pass' => 'password',
              'smtp_port' => 587,
              'crlf' => "\r\n",
              'newline' => "\r\n"
        ));


        $body = 'some html content';
        $this->email->set_mailtype("html");
        $this->email->from('noreply@domain.com');
        $this->email->to('to@userdomain.com');
        $this->email->subject('Please confirm your email');
        $this->email->message($body);
        $this->email->send();

It would be great if someone can help me understand what exactly is the issue.

Answer 1

The tutorial link is for Google Compute Engine. By default, the App Engine PHP environment runs in a mode where you won't be able to open arbitrary connections.

But, check out this guide instead: https://cloud.google.com/appengine/docs/php/mail/sendgrid