Issue emails not delivered in GSuite after migration from cPanel to Plesk

[Deleted member 209767]

Hi,
We just migrated from cPanel to Plesk and the mails stopped working after the migration. It was working perfectly fine for years with cPanel and we use this domain only for customer support (no newsletter or automated mails) so the domain was never blacklisted

We use coop@ni-dieu-ni-maitre.com with GSuite and the DNS is configured both in Cloudflare DNS and Plesk DNS Zone. A test with GSuite Toolbox CheckMX returns "No problems were found with the configuration of this domain"

If I log in my personal gmail account and send a mail to coop@ni-dieu-ni-maitre.com it works perfectly and the mail is received in GSuite

But it's not working when the same mail is sent by PHP mail() function. So our contact form is now broken (it was working with cPanel).

To test, we use this PHP script:

$to      = 'coop@ni-dieu-ni-maitre.com';
$subject = 'test mail to GSuite';
$message = 'Hello';
$headers = 'From: contactform@ni-dieu-ni-maitre.com' . "\r\n" .
    'Reply-To: customer_email@gmail.com' . "\r\n" .
    'X-Mailer: PHP/' . phpversion();
mail($to, $subject, $message, $headers);

$to      = 'my_personal_email@gmail.com';
$subject = 'Test mail to my personal gmail account';
$message = 'Hello';
$headers = 'From: coop@ni-dieu-ni-maitre.com' . "\r\n" .
    'Reply-To: customer_email@gmail.com' . "\r\n" .
    'X-Mailer: PHP/' . phpversion();
mail($to, $subject, $message, $headers);

The mail is NOT received in coop@ni-dieu-ni-maitre.com (GSuite) .. not even in the spam folder
However the mail is successfully received in my_personnal_account@gmail.com .. but in the header I can see "dkim=temperror (no key for signature)"

Here's the full header of the only mail i'm receiving in my_personnal_account@gmail.com ... I noticed the Return-Path is a different address but i'm not sure if it's a problem. I tried to change it to another email in php.ini using sendmail_from and sendmail_path, but it didn't change anything.

I already tried to contact Plesk support but it wasn't helpful. They blamed it on my domain even if it's not blacklisted. It was also working perfectly the day before the migration from cpanel to plesk .... And here's the thing : With GSuite I can send emails from coop@ni-dieu-ni-maitre.com and it is always successfully delivered. It doesn't work ONLY when sent by PHP mail() function.

 

[VojinP]

I suggest not to use plain php mail function, rather use PHPMailer with SMTP. Also check in mail settings for domain is "use DKIM" checked.

 

[Deleted member 209767]

I suggest not to use plain php mail function, rather use PHPMailer with SMTP.

But it was working for years on cPanel until the day we moved to Plesk ...

Also check in mail settings for domain is "use DKIM" checked.

Yes, it's checked

 

[VojinP]

It was working, but on cPanel you have an option to disable mail function, to use SMTP only. mail() is often used for spamming.