Someone on a coaching call asked me whether the daily sending numbers I give out are the max. Good question, because the instinct when you want more volume is to turn the dial up on the mailboxes you already have. That's the less safe way to get there. Here's what actually works, provider by provider. Microsoft is its own animal. You normally get 49 mailboxes per domain, and the warmup rules are different from Google. Keep it under 5 sends a day per mailbox. I'd start at 2 and watch that it's holding and delivering before I touch anything. Google and SMTP: we keep ours between 10 and 20 a day, with backups. If nobody's reporting you as spam and you're delivering well, there's no reason you can't slowly walk that up to 50. Google will technically let you send 2,000 a day. Obviously don't do that. Across the board, lower volume is better. Very low cold volume, warmup nice and high. That combination is what keeps the mailboxes and the domains protected. So when you need more sends, add more mailboxes and more domains. Scale it horizontally. Don't crank the volume on what you've got. It just keeps everything safer. One more thing, and it's the step people skip. Any time you load new mailboxes into Instantly (I'm pretty sure Smart Lead has this too), go in and turn on campaign slow ramp. You can bulk select them all. You don't want a fresh mailbox going from zero to 20 the same day. If you need high quality mailboxes(Google, Microsoft, SMTP): https://inboxinsiders.io/ How many mailboxes are you running right now, and what's each one sending a day?