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Infraforge

Mailbox infrastructure · pricing breakdown

Infraforge Pricing: The Line-Item Math of Dedicated-IP SMTP

Infraforge prices every isolation component on its own line, the mailbox, the dedicated IP, the SSL certificate, the domain masking. Here's how the bill actually assembles across volume tiers.

Aryan S
5 min readUpdated May 2026
Plans
3
Starts at
$2/domain/mo
Extra costs flagged
5
Updated
May 2026

Bottom line

Infraforge runs the most unbundled pricing model in this category. The per-mailbox SMTP rate, between $3 and $4 depending on volume, is one line item. The dedicated IP is its own $99 monthly fee.

SSL and domain masking is metered per domain at $2 each. API access and the masterbox come bundled into the per-mailbox rate, along with multi-IP provisioning and pre-warmed domains. What you end up with is a pricing surface built around one base unit and three add-on dials, which is unusual at this price point.

Most competitors pick either flat-per-mailbox or contract-based pricing; Infraforge goes line-item instead, giving compliance-minded teams the granular control to spell out exactly what isolation looks like at their volume. That same line-item structure, though, makes the bill genuinely harder to predict for buyers who haven't already mapped out their domain count.

Plan breakdown

Infraforge plans, side by side

SMTP Mailbox

$3-$4/mailbox/mo

rate varies depending on volume bracket

What you get

  • SMTP mailboxes on a dedicated IP fabric
  • Domains arrive pre-warmed at provisioning
  • API access plus webhooks
  • A masterbox console for managing the fleet
  • SPF, DKIM, and DMARC configure automatically

Watch out for

  • The dedicated IP is billed as its own charge
  • SSL and masking are billed per domain
  • SMTP-only, with no Google Workspace or Microsoft 365
  • Pre-warming happens once, not on an ongoing basis

Cost estimator

SMTP Mailbox(priced on a different unit)$3-$4/mailbox/mo
Dedicated IP Block$99/mo
SSL + Domain Masking(priced on a different unit)$2/domain/mo

Estimate built only from the list prices above. Excludes add-ons, taxes, overages and discounts, see “What’s not included” below.

On this page8
  1. 01Plan breakdown
  2. 02What's not included
  3. 03Cost at volume
  4. 04How the four-line-item pricing actually assembles
  5. 05Where the Infraforge bill breaks predictably
  6. 06How Infraforge fits in the Salesforge ecosystem
  7. 07Why compliance-led teams prefer the line-item structure
  8. 08FAQ

Read the fine print

What's not included

$99/mo flat, regardless of fleet size

The dedicated IP fee is the line item most buyers underestimate

A new buyer sees $3 to $4 per mailbox and budgets around that figure alone. The required dedicated IP, billed as a flat $99/mo on top, adds significant overhead for small fleets. At 10 mailboxes, where you'd expect somewhere around $30-$40/mo, the real bill lands at $130-$140/mo, since the IP fee stays constant no matter how many mailboxes you're running.

$2 per domain, $40-$100/mo at typical fleet sizes

Domain count is easy to underestimate when budgeting

Outbound teams typically spread sending across multiple domains for reputation diversification. A 100-mailbox fleet often runs across 15 to 30 domains as a safety margin. SSL and masking at $2 per domain adds up quickly at that scale: a 20-domain fleet adds $40/mo, a 50-domain fleet adds $100/mo.

Up to 33 percent variability per mailbox

The volume bracket for your rate isn't published transparently

The per-mailbox price ranges between $3 and $4 depending on which volume bracket you fall into, but those bracket thresholds aren't listed on the public pricing page. A 50-mailbox fleet might land in a different bracket than a 200-mailbox one. Confirm your bracket with sales before you size your budget.

$99 per additional IP block

Multi-IP provisioning is bundled in, but more IP blocks still cost extra

The ability to allocate multiple IPs across campaigns or clients is included with the dedicated IP block, but every additional block still costs its own $99/mo. A team that needs three IP blocks for agency client isolation is paying $297/mo just for IPs, before mailboxes even enter the math.

Ongoing warmup tool needed separately

Pre-warmed domains are a one-time boost, not ongoing warmup

Infraforge's pre-warming happens once, at provisioning: the domain arrives with warmup history already attached. There's no ongoing warmup tool to maintain or rebuild reputation afterward. If a mailbox's reputation degrades down the line, fixing it falls to your sender tool, not to Infraforge.

Cost at volume

What Infraforge actually costs at typical fleet sizes

  1. 1

    25 mailboxes, 5 domains

    ~$197/mo

    25 mailboxes at $3.50 each, plus the $99 IP fee, plus 5 domains at $2 for masking. Once the fixed IP fee is factored in, that's an effective $7.88 per mailbox, exactly why small fleets feel expensive here.

  2. 2

    50 mailboxes, 10 domains

    ~$294/mo

    50 mailboxes at $3.50 each, plus the $99 IP fee, plus 10 domains at $2 for masking. The effective per-mailbox cost drops to $5.88 as the IP fee spreads across more mailboxes.

  3. 3

    100 mailboxes, 20 domains

    ~$489/mo

    100 mailboxes at $3.50 each, plus the $99 IP fee, plus 20 domains at $2 for masking. Per-mailbox cost stabilizes around $4.89, roughly the size where Infraforge's line-item pricing starts becoming genuinely competitive.

  4. 4

    200 mailboxes, 40 domains

    ~$879/mo

    200 mailboxes at $3.50 each, plus the $99 IP fee, plus 40 domains at $2 for masking. Per-mailbox cost falls to $4.40. The volume bracket may also drop the base rate to $3 at this scale, confirm with sales.

  5. 5

    Agency with 3 client IP isolations

    ~$687/mo for 100 mailboxes

    100 mailboxes at $3.50 each, plus three IP blocks at $99 each, plus 20 domains at $2 for masking. Three separate IP blocks for client reputation isolation push the bill roughly 40 percent above the single-IP equivalent.

How Sendbox compares

Sendbox is the sending platform that sits on top: connect mailboxes from any of these providers, or provision them inside Sendbox. Plans start at $99/mo with dedicated IPs and the full deliverability suite included on every tier.

How the four-line-item pricing actually assembles

Infraforge's bill is a sum of four components: mailboxes ($3-$4 each), dedicated IP blocks ($99 each), SSL/masking ($2 per domain), and optional add-ons for multi-IP allocation. The structure rewards teams who understand exactly what they need at each level. Mailboxes scale linearly with your sending fleet.

IP blocks scale with how granular your reputation isolation needs to be (one block covers everything; multiple blocks separate client books or campaign cohorts). Domain SSL scales with how many sending domains you operate, which is typically 1 domain per 5 to 10 mailboxes for reputation diversification. The most common bill mistake is provisioning more domains than you need because the $2/domain fee feels small.

At 50 domains, that line alone is $100/mo, equal to a full IP block.

Key takeaways

  • Mailboxes scale with fleet size, $3-$4 each
  • IP blocks scale with isolation granularity, $99 each
  • SSL/masking scales with domain count, $2 each
  • Multi-IP provisioning is bundled into the IP block, not separate

Where the Infraforge bill breaks predictably

Three patterns where the bill diverges from a buyer's initial estimate: First, at small fleets (under 25 mailboxes), the $99 IP fee dominates the bill. Effective per-mailbox cost is two to three times the headline rate because the fixed fee amortizes over too few mailboxes. Teams in this band often complain about price; the fix is either scaling up or accepting that small SMTP fleets are not the target market.

Second, at multi-client agencies, the IP block multiplication can surprise. Three separate client reputations need three IP blocks = $297/mo just for IPs. The agency model on Infraforge is more expensive than the in-house model at equivalent mailbox count.

Third, at heavy-domain-rotation fleets, the masking fee compounds. Teams that rotate domains aggressively for cold email safety (a common pattern with anti-spam measures) can have 40+ domains, pushing masking past $80/mo.

Key takeaways

  • Small fleets pay 2-3x effective per-mailbox cost
  • Multi-client agencies pay per-client IP block stacks
  • High-domain-rotation fleets pay heavy masking fees
  • Mid-size fleets at 50-150 mailboxes hit the sweet spot

How Infraforge fits in the Salesforge ecosystem

Infraforge is the dedicated-IP tier of the Salesforge infrastructure stack. Mailforge is the shared-IP sibling at $2-$3 per mailbox. Buyers in the Salesforge ecosystem treat the two as the same product with different isolation guarantees, not as separate vendors.

The practical implication for pricing: if you start on Mailforge and grow into Infraforge, the migration is in-account (same login, same masterbox, same DNS setup). You do not re-onboard. The Mailforge-to-Infraforge upgrade is essentially adding the $99 IP block fee and moving mailboxes to the dedicated-IP fabric.

The Salesforge ecosystem assumption matters because it shapes who Infraforge is sized for. The pricing is aggressive for teams already invested in Salesforge sequences. It is less competitive for teams shopping cold and comparing across vendor families.

Key takeaways

  • Infraforge is the dedicated-IP tier of the Salesforge stack
  • Mailforge to Infraforge is an in-account upgrade, not a migration
  • Pricing assumes you are already in the Salesforge ecosystem
  • Cold buyers comparing across vendors see less of the advantage

Why compliance-led teams prefer the line-item structure

For most cold email buyers, flat per-mailbox pricing is easier to budget. Compliance-led buyers (regulated industries, financial services, healthcare-adjacent SaaS) often prefer line-item structures because they can audit exactly what isolation is included at what cost. The line items on Infraforge map cleanly to compliance requirements: dedicated IP (one tenant per IP for SPF auditability), SSL per domain (TLS auditability), multi-IP provisioning (cross-client isolation for B2B2B agencies), per-mailbox pre-warming (reputation history auditability).

The trade-off is that compliance buyers also pay more per unit because they need every component. Cost-conscious buyers usually find the same isolation level cheaper inside a bundled product like InboxKit. Choose by which side of the compliance/cost axis you operate from.

Key takeaways

  • Line items map to compliance audit requirements
  • Dedicated IP, SSL, masking, and warmup history are each verifiable
  • Compliance buyers pay more but get auditable isolation
  • Cost-conscious buyers prefer bundled-IP alternatives

Sources

InfraforgeG2Website
faq

Got questions? We've got answers.

Roughly $489/mo at typical configuration: 100 mailboxes at $3.50 each = $350, plus $99 for the dedicated IP block, plus $40 for SSL/masking on 20 domains. Per-mailbox effective cost is $4.89. The exact rate depends on your volume bracket; confirm with sales before sizing your bill.

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