This is an unfortunate limitation of Joomla! itself. Even though RFC 5322 allows for lists of email addresses, Joomla's email
field type and the email validation rule do not.
This is not a new thing; it's been the case since Joomla! 4.0, and that's because we moved away from using our own framework, instead using Joomla's own CSS framework. That's why the help text has been changed to read "enter an email address" (singular), instead of previous versions which told you that you can enter a list of email addresses.
If you want to send to multiple email addresses you need to create a mail forwarder in your site's hosting control panel. For example, you could have the forwarder address [email protected] which forwards to [email protected], [email protected], and [email protected]. Therefore, putting the address [email protected] in the Configure WAF page would end up emailing all three addresses.
Nicholas K. Dionysopoulos
Lead Developer and Director
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