One thread per person. Every channel.
The thing no other CRM does: Quarters merges iMessage, SMS, email, and Slack — plus your calendar — into a single timeline for each contact, threaded automatically by who they are, not which app they used. The text you sent from your phone sits right next to the email you sent from your laptop and the Slack reply from this morning.
Identity resolution — one person's phone number, two email addresses, and a Slack handle all collapse onto one card, so nothing scatters across half-built duplicates. And full history — pull a contact's complete email history on demand, and see exactly how complete your coverage is.