How does the one-click export work?

Select mailboxes in CLAYINBOX, hit Export, choose Smartlead. App passwords, tracking domains, and per-account settings transfer automatically.

Whose warmup should I use?

Use CLAYINBOX' isolated warmup. Smartlead's network is a shared pool unless you pay for SmartServers.

What if Smartlead disconnects an account?

Reconnect via OAuth or app password from the CLAYINBOX dashboard. Free replacements if the mailbox itself burned.

// HEAD-TO-HEAD

CLAYINBOX + Smartlead: better together (and cheaper than SmartSenders)

Smartlead is one of the best sequencers in cold email — and CLAYINBOX is built to plug into it. This page compares CLAYINBOX mailboxes against Smartlead's own SmartSenders inbox offering, not against Smartlead the platform.

Get Mailboxes →See Pricing✓ Works with Smartlead

Last verified: June 2026

// TL;DR VERDICT

Choose Smartlead if: you want everything billed inside one Smartlead invoice and same-vendor support when a connection breaks.
Choose CLAYINBOX if: you want your infrastructure independent of your sequencer (portability if you ever switch tools), at $2.50/mailbox vs $4 + $15/domain/yr, with monitoring, free replacements, a unified inbox, and Azure/SMTP options SmartSenders doesn't offer.
Bottom line: keep Smartlead for sending. Buy the layer underneath it wherever it's best — and portable.

// FULL COMPARISON

Feature by feature

Feature	CLAYINBOX	Smartlead
What it is	Independent infrastructure layer	Mailboxes sold inside Smartlead (partner program)
Mailbox price	$2.50/mo flat	$4/mailbox/mo + $15/domain/yr
Providers	GW, M365, Azure, SMTP	Google and/or Outlook
Admin access	✓ full	✓ full (Standard tier)
Portability	Use with ANY sequencer, switch anytime	Tied to the Smartlead ecosystem
Warmup	Included, isolated	Smartlead's warmup network (shared pool; private via SmartServers)
Monitoring / placement tests	✓ included free	Via Smartlead plan features/add-ons
Free replacements	✓ unlimited	Per partner policy
Unified inbox	✓ infra-level	Smartlead Master Inbox (sequencer-level — both useful)
Domain isolation	✓ per-domain workspace	✓ unique workspace per domain
Connection	One-click export to Smartlead	Native
Sequencer cost on top	Smartlead from $39/mo (unlimited sender accounts)	Same

// THE REAL MONTHLY BILL

What 50 mailboxes actually costs

SMARTSENDERS ROUTE

50 × $4.00$200.00

10 domains × $15/yr$12.50/mo

Smartlead Basic$39.00

Total~$251/mo

CLAYINBOX ROUTE

50 × $2.50$125.00

10 domains $13/yr$10.80/mo

Smartlead Basic$39.00

Total~$175/mo

+ monitoring + free swaps included on CLAYINBOX

Where Smartlead is genuinely good

As a sequencer Smartlead is the agency benchmark — unlimited sender accounts from $39/mo, white-label client portals, ESP matching, SmartServers for private reputation control, and an API technical teams love. None of that changes; CLAYINBOX exists to feed it better mailboxes.

Where CLAYINBOX pulls ahead

Price ($2.50 vs $4 + domain fees), provider breadth (Azure density and dedicated SMTP don't exist in SmartSenders), independent monitoring, free unlimited replacements, and above all portability — if you ever move from Smartlead to another tool, your domains, mailboxes, and reputation come with you instead of being marooned in a partner program.

How the pairing works

Provision on CLAYINBOX, one-click export pushes accounts, app passwords, and tracking domains straight into Smartlead. Replies flow through Smartlead's Master Inbox; infrastructure health flows through our monitoring. Two dashboards, zero overlap.

// FAQ

Common questions

No — it replaces SmartSenders, the mailbox offering inside Smartlead. Keep Smartlead as your sequencer.

// NEXT

Provision mailboxes that don't need add-ons.

Flat $2.50/mailbox. Warmup, monitoring, replacements, unified inbox — all included.

Get Mailboxes →See all comparisons

// COMPARE OTHERS

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