Randomly missing WooCommerce emails

Hi @tomz6,

Thanks for the detailed report and for sharing your system status! The fact that CF7 and registration emails are going through fine but WooCommerce order emails are intermittently falling back to the local server is an interesting clue, and a few things in your setup are worth investigating further.

Before we dig in, a few questions to help us narrow this down:

• Since you have the WP Mail Logging plugin active, could you check the logs (WP Mail Log → Log) for a few of the orders where emails went missing? We’re looking for two things: whether those emails appear in the log at all, and if so, which mailer/connection they show as being sent through. That will tell us if WooCommerce is even attempting to send them via FluentSMTP.
• Could you also check FluentSMTP → Email Logs for the same time periods? If the emails don’t appear there at all, that points to WooCommerce bypassing FluentSMTP entirely for those sends.
• Which email types are affected? Is it always the same type of order email going missing (e.g. new order notification, processing, completed), or does it vary?
• Go to WooCommerce → Status → Logs and check for any entries related to emails around the times the failures occurred. Anything there would help.

One thing also worth noting: your system report shows a custom template override for customer-completed-order.php in your child theme. If that file is outdated relative to the current WooCommerce version it could potentially cause issues with how that specific email is triggered, worth keeping in mind depending on which email type is affected.

Let us know how that goes!

Hi there!

Thanks for the follow-up and for checking those logs.

From the WooCommerce side, what you describe tells us that WooCommerce is triggering the emails (because they show up in WP Mail Logging) but, for some of them, the actual delivery is not being handled by FluentSMTP/Microsoft 365. Since WooCommerce uses the standard wp_mail() function for all its core emails, any decision about whether a message goes via the local server or via Microsoft 365 happens in the mailer layer (SMTP plugin, hosting, or other custom code), not in WooCommerce itself.

Because of that, there are a couple of WooCommerce‑specific checks you can still make:

• In WooCommerce → Settings → Emails, confirm that the affected email types (New order, Completed order) are enabled and that their recipient, “From” name, and “From” address are set as expected (no typos, no empty fields, and using a valid address).
• You mentioned a custom code snippet that automatically moves orders from processing to completed and that you have a custom template override for customer-completed-order.php in your child theme. Both of these run at the point where the completed order email is triggered, so if they are outdated or hooking into the email actions differently, they can affect when/how that email is sent. As a WooCommerce core support team we can’t review or debug custom code here, but as a test you can temporarily disable the auto‑complete snippet and/or switch to the default email template (by renaming the overridden file in your child theme) and then place a test order to see if the Completed Order email behaves more consistently.

If, with the default WooCommerce email templates and without the custom auto‑completion code, the emails consistently appear in your SMTP logs and send as expected, that would indicate the issue lies in customizations or the mailer configuration rather than in WooCommerce core. In that case, the next step would be to reach out to the FluentSMTP support team and/or your developer to review the custom code and routing rules in detail, as that goes beyond what we can cover in this forum.

From our perspective, there is no setting in WooCommerce core that selectively bypasses your configured mailer for some order emails but not others, so WooCommerce will always hand the email off to wp_mail() in the same way whenever those email events are triggered.

let us know what you find.