Post SMTP – Office 365 connection issue

Strange, where do you host?

I’m hosting with Digital Ocean; I have just done a test using a temporary Gmail account set up to use OAuth and that’s also giving the same error.

There is an error getting your hostname

What do you get when you type in the command line:
hostname

Hello again – I’m getting the hostname london-drainage at the moment, just checking the hosts file to see if there’s a reason for it showing that in preference to the full domain name.

I’ve now updated the hostname to a full URI and unfortunately I am still seeing

'' does not match the expected structure for a DNS hostname, '' does not appear to be a valid URI hostname, '' does not appear to be a valid local network name

If you did ok you should see your hostname in the diagnostic test.
Paste it here

HostName: 
OS: Linux london-drainage.co.uk 4.4.0-133-generic #159-Ubuntu SMP Fri Aug 10 07:31:43 UTC 2018 x86_64
PHP: Linux 7.0.13-0ubuntu0.16.04.1 en_US.UTF-8
PHP Dependencies: iconv=Yes, spl_autoload=Yes, openssl=Yes, sockets=Yes, allow_url_fopen=Yes, mcrypt=Yes, zlib_encode=Yes
WordPress: 4.9.8 en_US UTF-8
WordPress Theme: X – Child Theme
WordPress Plugins: 404page - your smart custom 404 error page, Contact Form 7 Google Analytics Integration, Contact Form 7 Modules: Hidden Fields, Contact Form 7, Cornerstone, Duplicator, Flamingo, Google Analytics for WordPress by MonsterInsights, Attercopia London Drainage Search, Page/Post Content Shortcode, Post SMTP, Redirection, Simple Custom CSS, UberMenu 3 - The Ultimate WordPress Mega Menu, UpdraftPlus - Backup/Restore, WonderPlugin Tabs, Yoast SEO, WP Fastest Cache, Smush, Contact Form 7 Redirection
WordPress wp_mail Filter(s): wp_staticize_emoji_for_email
WordPress phpmailer_init Action(s): wpcf7_phpmailer_init
Postman: 1.9.4
Postman Sender Domain (Envelope|Message): london-drainage.co.uk | london-drainage.co.uk
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Active Transport: SMTP (smtp:tls:login://smtp.office365.com:587)
Postman Active Transport Status (Ready|Connected): Yes | Yes
Postman Deliveries (Success|Fail): 0 | 0

I want to make clear we are stepping out from the plugin support scope, you have an issue with server configuration. I’m interested to understand the issue so I will continue trying to solve it with you.

Please verify you have this line in your hosts file located at /etc/hosts:

127.0.1.1 london-drainage.co.uk london-drainage
127.0.0.1 localhost

if you want to know your full hostname you can type
hostname -f

• This reply was modified 6 years, 3 months ago by yehudah.

Thank you for your assistance so far; I have raised a support ticket with our hosting partners as well to see if we can resolve this.

Yes, we do have those two lines exactly as entered in our /etc/hosts file.

Can you restart the server, and paste the first line of the diagnostic test,?

What I’m currently seeing on the Diagnostic test is:

HostName: 
OS: Linux london-drainage.co.uk 4.4.0-133-generic #159-Ubuntu SMP Fri Aug 10 07:31:43 UTC 2018 x86_64

The hostname -f command through SSH is showing
london-drainage.co.uk

Not sure if it helps, but the server is using NGINX and this is the first time we’ve encountered this particular issue with Post SMTP using the same server setup.

I’ve been discussing this with our hosting partners, and they have confirmed that they are not seeing any problems on the platform or server-side based on the information we’ve provided them (the same as we’ve provided here) – and that the hosting server has a valid rDNS record matching the server’s hostname of https://www.london-drainage.co.uk (they did recommend we update this to https://www.london-drainage.co.uk as a FQDN).

Hi,

Please upload this PHP file to the root of your website and run it.
Update what was the result here:

        echo getServerName(); 

	function getServerName() {
        $result = 'localhost.localdomain';
        
        if (isset($_SERVER) and array_key_exists('SERVER_NAME', $_SERVER)) {
            $result = $_SERVER['SERVER_NAME'];
        } elseif (function_exists('gethostname') and gethostname() !== false) {
            $result = gethostname();
        } elseif (php_uname('n') !== false) {
            $result = php_uname('n');
        }

		if ( $result !== 'localhost.localdomain' ) {
			// get the current result ip
			$ip = gethostbyname($result);

			// dns query failed
			if ( $ip == $result ) {
				return $result;
			}

			// get the current ip hostname - reverse dns
			$host = gethostbyaddr($ip);

			// dns query failed
			if ( $host == $ip ) {
				return $result;
			}

			// if hostname is not equal to the result set the ptr
			if ( $result !== $host ) {
				$result = $host;
			}
		}

        return $result;
	}

What I’m seeing on running that code is a blank page, with no visible result displayed.

Try this:

<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

echo getServerName(); 

function getServerName() {
$result = 'localhost.localdomain';

if (isset($_SERVER) and array_key_exists('SERVER_NAME', $_SERVER)) {
    $result = $_SERVER['SERVER_NAME'];
} elseif (function_exists('gethostname') and gethostname() !== false) {
    $result = gethostname();
} elseif (php_uname('n') !== false) {
    $result = php_uname('n');
}

	if ( $result !== 'localhost.localdomain' ) {
		// get the current result ip
		$ip = gethostbyname($result);

		// dns query failed
		if ( $ip == $result ) {
			return $result;
		}

		// get the current ip hostname - reverse dns
		$host = gethostbyaddr($ip);

		// dns query failed
		if ( $host == $ip ) {
			return $result;
		}

		// if hostname is not equal to the result set the ptr
		if ( $result !== $host ) {
			$result = $host;
		}
	}

       return $result;
}