Some order emails duplicated and some don’t reach our mailbox

Hey there, @tauclement! Thanks for contacting us. I’m happy to help you.

Do you mind sharing more details about this?

I know you mentioned it happened randomly, but can you please check to see if you find any patterns to them?

For example, are the ones that have issues always an email about the same thing (eg. new order email, low stock email, etc)?

If the emails that have the issue are regarding orders, are there any similarities between the orders?

You mentioned you installed WP MAIL Logging. For the emails that do not reach your mailbox, do you see on WP MAIL Logging that they were sent?
And do you see the duplicates on WP MAIL Logging?

Furthermore, I’d like to understand your site properly. Please share with us the necessary information below for us to investigate the issue further:

System Status Report which you can find via WooCommerce > Status > Get system report > Copy for support.
Fatal error logs (if any) under WooCommerce > Status > Logs. Then you can use the selector to search for Fatal Errors.
You could copy and paste your reply here or paste it via https://gist.github.com/ and send the link here.

Looking forward to your reply.

Have a wonderful day!

Hello, the emails are mainly for New Orders where they don’t deliver and the duplicates ([Cellucity]: New order #33993).
These orders are in processing on the back end but we never got these orders.

Order number 33853 Date : 28/05/24

Order number 33814 Date : 27/05/24

Order number 33992 Date 30/05/24

Ive shared the files on the following link.
https://gist.github.com/tauclement/7755ef72c664b422d36e8704cfbbfcb2

Hi @tauclement

Thanks for sharing additional details. I appreciate your efforts in troubleshooting this issue by checking your spam folder, verifying your SMTP settings, and consulting with your hosting company.

This issue could be related to many factors, including email server settings, a plugin conflict, or a problem with the email address being used. Here are a few steps you can take to diagnose further and possibly resolve the issue:

1. Ensure the email address you’re using as the sender email is not the same as your server’s default email address. This can sometimes cause issues with email delivery.
2. Try disabling all plugins except for WooCommerce and WP Mail Logging, then test your email notifications. If the issue resolves, it could be a plugin conflict. You can then reactivate your plugins one by one, testing your emails each time, to identify the conflicting plugin.
3. If the issue persists, you might want to consider using a transactional email service, like SendGrid or Mailgun. These services are designed to improve email deliverability and could help resolve your issue.

If the issue still continues, please review our email sending FAQ for help, troubleshooting steps, and solutions here: https://woocommerce.com/document/email-faq/

I hope this helps! Please let us know how it goes or if you need further assistance.