Quick answers to the questions every team asks: how much volume is safe, why placement differs from delivery, whether images and links hurt, and when to add domains vs mailboxes.
How much can I safely send?
100–150/day per warmed mailbox, 2–4 mailboxes per domain. Scale by adding mailboxes and domains, never by pushing per-mailbox volume past the caps.
Delivered ≠ inboxed?
Correct. "Delivered" means accepted by the receiving server; it may still land in spam or promotions. Placement tests measure where it actually lands — that's the number that matters.
Do images and links hurt?
In cold outbound, yes at the margin: heavy formatting reads as marketing mail. Plain-text-style messages with at most one link consistently place better for first touches.
New domain or new mailbox?
Need +100–150/day → add a mailbox to an existing healthy domain (2 weeks to warm). At 4 mailboxes on a domain → add a domain (buy, authenticate, warm — allow 3–4 weeks before full contribution).