<b>Inbox rotation: the feature, not just the count</b>

<b>Inbox rotation: the feature, not just the count</b>

'Unlimited mailboxes' is a pricing line. How the tool rotates them is what saves your domains.

What to actually compare
— Per-mailbox daily cap enforcement (Smartlead and Instantly both throttle; some cheaper tools don't)
— Whether one lead receives all follow-ups from the same inbox (it should — switching mid-sequence looks bot-like)
— Auto-pause when a mailbox's reputation drops, not just on hard bounce

Smartlead
— Pros: thread continuity per lead, configurable caps, auto-pause on health drop
— Cons: setup complexity

Instantly
— Pros: simple rotation, good defaults
— Cons: less granular cap control

The failure mode: tools that round-robin every email across mailboxes split a single conversation across three senders. Prospects notice. So do spam filters.

Verdict: 4/5 — rotation is table stakes, but thread continuity per lead is the line between cheap tools and real ones.

Who it's for: multi-domain senders past 10 mailboxes.