Deliverability checklist before you send anything

SPF, DKIM, and DMARC configured and passing; every new inbox warmed for 2-3 weeks before real volume; sending spread across multiple domains/inboxes rather than one; bounce rate kept under 2% and spam complaints under 0.3% (Google/Yahoo/Microsoft now enforce these thresholds for bulk senders); a working one-click unsubscribe. Skipping any one of these caps how much volume you can safely send regardless of copy quality.