When we register a group of contacts to a Civi event we don't want a confirmation email to be sent (as the registration is for internal purposes). If you register one person at a time the checkbox can be unchecked, but for mass registration this doesn't seem possible. I can see there was an extension back in 2015 which appears to offer the solution but it doesn't appear in my list of extensions now. Is it still valid or is there an alternative solution now? Thanks
If you are on 5.26+ CiviCRM version, when you find contact, select list of contact and use 'Register participants for event' from the action list. It takes you to the Create participant form. When you select the event, there will an option for 'Registration Confirmation and Receipt' at the end of the form where you can select or unselect send receipt option.
You can try on https://dmaster.demo.civicrm.org/
Do you refer to the sendeventconf extension that can be found at https://github.com/TechToThePeople/sendeventconf ?
It's a basic extension and it most likely works. So, it makes sense to try. Installation of an extension not found on the list is documented at https://docs.civicrm.org/sysadmin/en/latest/customize/extensions/#installing-a-new-extension. You can download the extension code at https://github.com/TechToThePeople/sendeventconf/archive/refs/heads/master.zip
You may want to have a look at our new extension "Event Messages". It provides an alternative way to send confirmation emails for CiviCRM Events. It creates an additional tab within CiviCRM Events that allows you to define different message templates to be sent based on conditions (including the participants status, role and preferred language). It will also allow you to suppress CiviCRM's regular emails.
It aims at providing an easier way to adapt event confirmation mails than editing the system workflow messages provided by CiviCRM.
As the extension is still under active development, please read the limitations/known issues.