Only the first participant is emailed for an event.
I have calendar 3.2.19 installed with libcalendaring. Everything appears to be working except when adding/editing an event with more than one participant. The first person gets an email but the second one does not. And Roundcube displays an error dialog about not being able to email recipients. "Failed to send notifications to event participants"
Roundcube errors log has this:
[06-Sep-2018 09:14:24 -0400]: <ivrnidlh> SMTP Error: 250: 2.0.0 Ok: queued as EC59099
No From address has been provided in /var/www/roundcube/program/lib/Roundcube/rcube.php on line 1648 (POST /webmail/?_task=calendar&_action=event)