Warmup Inbox vs Folderly 2026: $15 vs $96/Inbox

Warmup Inbox vs Folderly at a glance

Warmup Inbox undercuts Folderly on price at every tier, but Folderly is the only one of the two that tests actual spam placement across Gmail, Outlook, and Yahoo. Five plans across both tools show the gap in what you're actually paying for, not just the sticker price.

Folderly's pricing jumps hard between tiers, per Folderly's pricing page, while Warmup Inbox keeps a flatter curve, per Warmup Inbox's pricing page. That difference matters more once you're past 20 inboxes.

Warmup volume: Warmup Inbox sends more, Folderly sends smarter

Warmup Inbox runs unlimited warmup emails across a shared reply network of other warmed inboxes, pushing volume up fast in the first two weeks. Folderly caps warmup volume lower by design because it prioritizes placement accuracy over raw send count, per Folderly's documentation.

For a brand-new domain, volume is what matters most in week one. Warmup Inbox's shared network gets you to 30-40 warmup emails a day faster than Folderly does. We've run this exact pattern across 6,000+ campaigns at Modern Inbound: a new domain needs volume before it needs diagnostics.

1. Warmup Inbox

From $15/mo · Best for teams warming 5-50 inboxes on a budget · Unlimited warmup volume across a shared reply network

Setup takes under 10 minutes per inbox, and pricing scales in flat tiers instead of per-seat fees. You won't find placement testing or DNS scoring here, and you shouldn't expect it at this price.

For agencies running client inboxes, the shared warmup network is the real value. Your new domains borrow reputation from inboxes that have already been warming for weeks.

Where it falls short: once you're actually in spam, Warmup Inbox gives you zero diagnostic data. You'll keep warming an inbox that's blacklisted and never know it.

2. Folderly

From $96/mo · Best for teams actively fighting a spam-placement problem · Spam-placement testing across Gmail, Outlook, and Yahoo

The DNS scoring catches misconfigured SPF and DKIM records that most teams never check until it's too late. That diagnostic layer is genuinely absent from Warmup Inbox and most cheap warmup tools.

Folderly's dashboard shows which specific inbox provider is blocking you, Gmail versus Outlook versus Yahoo, instead of a single blended score. That specificity is the actual product.

Where it falls short: the annual contract and $96+ starting price punish you for testing the water. If you're not sure you have a placement problem yet, you're overpaying to find out.

Total cost for 10, 30, and 100 inboxes

At 10 inboxes, Warmup Inbox runs about $39/mo total versus Folderly's $960/mo if billed per inbox on an annual contract. That gap only closes if Folderly's diagnostics actually fix a placement problem Warmup Inbox can't see.

• 10 inboxes: Warmup Inbox around $39/mo. Folderly's Starter at $96/mo per domain, most teams run it per domain rather than per inbox.
• 30 inboxes: Warmup Inbox's Growth tier at $39-79/mo. Folderly's Pro at $199/mo scales with sending domains, favoring Folderly once you've consolidated inboxes under fewer domains.
• 100+ inboxes: Neither sticker price matters as much as whether your domains are getting through. Most teams we work with at Modern Inbound run both: Warmup Inbox for volume, Folderly for the domains that keep underperforming.

Pick Warmup Inbox under 50 inboxes with no confirmed spam problem. Pick Folderly once you've got evidence emails are landing in spam and need to know exactly where.

If you'd rather not manage warmup, DNS, and deliverability tooling yourself, that's the execution layer Modern Inbound's Setup service handles end to end: domains, mailboxes, 14-day warmup, and deliverability included.

Want Research-Led Outreach Run For You?

Modern Inbound mines buyer language, builds account lists, writes outreach, manages client-owned inboxes, and routes qualified replies. Your team gets sales conversations, not another tool to operate.