When registring no email to the registrant

Hi

If the email is in the email history, then the email was sent by HikaShop to the email server of your hosting so that it can be sent to the receiver.
Either the email was not sent by the email server as it found a problem with it (for example, if the receiver email address and the sender email address are the same), or the email was rejected by the receiver email server, or it ended up in its spam folder.

What happened exactly it hard to say from HikaShop's point of view. If you don't see any error about the email being sent, then it means that the email server of the hosting told HikaShop that the email had been successfully taken into account on its end and thus HikaShop has no way of knowing what happened after that.
First thing is to check if the email didn't end up in the spam folder of the receiver. If it's a spam problem (and it's likely), the best is to check the email with www.mail-tester.com/ service. It will tell you what's wrong with the email setup.
Second thing is to contact your hosting support so that they can check the log of the email server for that email (you can give them a screenshot of the email information from the email history in HikaShop). If the problem happened on the sender email server or on the receiver email server, the log of the sender email server should contain information about the problem.

Hi,

That's indeed strange.
Regarding where the sending happens... It's in several places.
In HikaShop the sending happens in the sendMail function of the file administrator/components/com_hikashop/classes/mail.php
As you'll see, it actually uses the Joomla mailer library's "send" function for that. The JMail class of the Joomla mailer is defined in the file libraries/src/Mail/Mail.php on Joomla 3.9. This class has a "send" function which actually calls the send function of the parent class PHPMailer which is defined in libraries/vendor/phpmailer/phpmailer/class.phpmailer.php
This send function calls the postSend function in the same class and from there, it depends on how your Joomla configuration emails settings are configured.

Hi,

So you mean that the email was not delivered to the recipient because the URL of the activation link in it is too long ? Or are you talking about a new problem ?
The second half of your link is unnecessary.
The part "&task=activate&activation=8b1c8a5b0e18c34bdd258a326f37c6e6&infos=eyJwYXNzIjoicG9saWsiLCJ1=t1ZC6B&Ipage&Jid=9id=9id=11&Jid=11&Jid=11&Jid=11&Jid=9idm" at the end is not useful.
Only the first part www.chassart.com/index.php?option=com_hi...G9saWsiLCJ1FltC2Si6b is useful and that's what the activation link looks like by default in HikaShop.
I don't know where the rest of the link comes from on your website. There are no Jid parameters in URLs generated by HikaShop. So it seems that the URL has been processed by something at some point.