Lemme say again what I've already said in the articles/links I shared before:
Zen Cart uses the SAME email delivery logic for both the admin and the storefront operations.
Zen Cart always "sends" the emails. If an email fails to be "sent" (ie: handed off to the mailserver so it can be delivered thru all the email server networks), then an error message will be displayed immediately.
So, if you are not RECEIVING those emails, then something is interfering with the delivery.
Or you've changed the Zen Cart code so that it can't actually hand off the emails.
As explained in the articles I mentioned, often the use of the "PHP" setting for transport protocol will prevent delivery because the mailserver doesn't "trust" the webserver, since unauthenticated emails are exactly how spammers work. Thus using SMTPAUTH and providing credentials to use it, can usually mitigate that issue. That's in the docs I mentioned.
Also in the articles I mentioned, is advice about using the Email History Archive feature to see what Zen Cart is actually sending. The articles explain that the sent emails (except for password resets) will be stored to the email archive table when the feature is enabled, only when ZC hands off an email to the mailserver. There is an Email Archive Manager addon that can let you see what's in the archive. So if an email is in the archive (and the archiving is enabled), then the email was in fact "sent" and any inability to deliver the email is entirely in the hands of all the email servers responsible for delivery, and not Zen Cart.
So I would recommend you consider those investigative steps.
And if for some reason those don't lead you to a solution, then please give detailed results of all the things you've done to sort out this situation, including those I've not specifically re-typed here, but also those discussed in the other articles mentioned.
It's really difficult to help you sort out something that works properly out-of-the-box for thousands of stores, but mysteriously not for your specific situation ... without details about what makes your situation unique vs all the others.
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