Currently, sending a bulk outbound email to a specific list of people requires: uploading a CSV via "Filter audience from CSV," having those contacts already exist in Intercom (the CSV only filters/tags existing users and leads — it doesn't create new ones), tagging them, then building an audience rule around that tag. If any of the target emails aren't already in Contacts, the CSV filter simply won't find or tag them, so they're silently excluded from the send.
In practice this means before sending to a list, we first have to import those emails as contacts, then run the CSV filter to tag them, then build the message around the tag - and clean up duplicate contacts created in the process. For a simple "send this email to this list of people" task, that's a lot of manual setup and prone to errors (duplicates, silently dropped recipients).
We'd like a simpler option: either paste a list of email addresses directly into the outbound message audience, or upload a CSV of emails, and have Intercom send to exactly those addresses - regardless of whether they already exist as contacts. This would remove the need to pre-populate Contacts just to do a one-off bulk send.