Is it possible to have the email a notification pipeline sends have all the recipients on the "To" line. I would like it if people that receive the email can "reply all" so they can discuss the topic of the email.
Not via the notification block, no. Because the unique identifier in the email is what's used to know who actually acknowledged the alarm; that's why the system sends one email to one person at a time.
You could use a script block and
system.net.sendEmail to send your own email to whomever you want, though. But you won't be able to acknowledge back from it.
Using system.net.sendEmail and a script block worked perfectly. For my application I don't need the acknowledgment function. Thanks for the help.