Cold email infrastructure for SaaS companies

01

Who this is for

The buyer here is a B2B SaaS founder doing outbound before the first sales hire, or a small SDR team of a few reps that sends email only. They need domains, mailboxes, warming, a sequencer, a shared reply inbox and a light pipeline, and they would rather pay one bill for those than assemble five tools. The sequencer is included on every plan, so there is no per-seat fee for reps and no separate fee per campaign.

It fits less well when outbound is already a mature motion with a lead-data vendor, a CRM sync and a team of specialists. Those teams usually need a mature sequencer and integrations more than they need bundled infrastructure, and the section on where to look elsewhere is written for them.

02

Mailbox and domain math at 50, 200 and 600 mailboxes

Plans are priced on mailboxes. Starter is $69/mo with 50 mailboxes and 50 domain slots, Growth is $189/mo with 200 and 200, Scale is $499/mo with 600 and 600. Warming is an optional $0.60 per inbox per month, and almost every sender should turn it on, so the table adds it. The daily figure is mailboxes times the default of 15 cold emails per inbox, which is a ceiling at the default and not a promise of what you will reach.

50 mailboxes: Starter $69 plus $30 of warming is $99/mo, or about $1.98 per mailbox, and 750 sends a day across 9 to 13 domains. 200 mailboxes: Growth $189 plus $120 of warming is $309/mo, about $1.55 per mailbox, and 3,000 sends a day across 34 to 50 domains. 600 mailboxes: Scale $499 plus $360 of warming is $859/mo, about $1.43 per mailbox, and 9,000 sends a day across 100 to 150 domains. Domain slots match the mailbox count on each plan, so the slots never bind at four to six mailboxes per domain.

Domains are a one-time registration from a prepaid balance, from $1 for some TLDs up to about $10 for .com on the pricing page, so 9 to 13 domains is roughly $9 to $130 once. POST /domains/search returns the exact price before you buy. Leased pre-warmed inboxes are on top of all of this: $3/mo each, not counted against the plan’s mailbox allowance.

03

Where the plan boundaries fall

Extra mailboxes are $1/mo each beyond the included count, up to a hard ceiling of three times it: 150 on Starter, 600 on Growth, 1,800 on Scale. Past the ceiling a request is refused and the message asks for a conversation first. Each extra mailbox also unlocks a matching domain slot. 200 mailboxes cannot run on Starter at all, because the ceiling is 150.

Between the ceilings, compare the totals. Starter plus overage costs $69 plus $1 per mailbox above 50, which passes Growth’s $189 at 170 mailboxes. Growth plus overage passes Scale’s $499 at 510 mailboxes. At 600 mailboxes Growth with 400 extra is $589 against Scale’s $499, so Scale is the cheaper way to hold 600 even though Growth could reach it. Warming is $0.60 per inbox on every plan, so it does not change those crossover points.

04

What is included in the plan fee

Every plan includes the Engage sequencer, the Unibox, the CRM, list verification, the REST API and MCP server, and automatic SPF, DKIM, DMARC and MX. Nothing in the sequencer, Unibox or CRM differs between Starter and Scale: the plans differ in mailboxes, domain slots and daily verification checks, and in extras such as dedicated IPs ($20/month, listed for Growth and Scale).

Sequencer: multi-step campaigns of up to 10 steps with up to 6 A/B variants each, up to 5 schedules per campaign in a time zone you choose, merge fields with fallbacks, a campaign daily limit, mailbox rotation and priority between campaigns that share a mailbox. A lead stops when it replies, and a launch check runs first. Unibox: one inbox for replies from every mailbox, filtered by status, campaign or mailbox, with reminders, scheduled replies and reply templates. CRM: lead statuses, a pipeline with stage probabilities, opportunities (a positive status opens one), tasks, lists, CSV import with optional verification, and reports for conversion by campaign, leads by status and pipeline by stage.

Warming is not in the plan fee: it is $0.60 per inbox per month and can be switched off per mailbox. The sequencer went live on 5 October 2026, so it has no track record, and the Unibox help article documents status, reminders, scheduled replies and templates but not assigning a thread to a rep.

05

What you still bring: leads and CRM glue

EmailPal has no lead database, email finder or enrichment. Leads come from your own sources by CSV or paste, and the Terms require lists you collected from identifiable sources, not purchased, rented or scraped ones. Verification is built in and runs per address before you send.

There are no native HubSpot, Salesforce, Pipedrive or Zapier connectors. What exists is the REST API and signed webhooks. reply.received fires when a prospect answers a campaign email and carries the campaign, step, variant and whether it stopped the sequence, and lead.status_changed fires on every status change. A developer on your team can push both into your CRM; nothing does it for you. The account allows ten webhook endpoints.

06

Sending limits and the safeguards that apply

The recommended default is 15 cold emails per inbox per day, with a hard cap of 100 that no setting exceeds. Warming traffic is separate and does not count against it, and replies you send from the Unibox do. More volume means more mailboxes on more domains, not a higher cap on one: the mailbox form suggests four to six per domain (about five), warns past about 10 and does not block more on a domain you own.

A campaign pauses automatically when hard bounces reach its limit (5% by default, adjustable from 0.5% to 5%) after at least 200 sends. Separately, a mailbox pauses its campaign sending when 5% of its cold mail is rejected by the receiving server, with a warning email at 3%. Complaints and unsubscribes suppress the contact but do not pause a campaign. These are protections for the infrastructure, not a guarantee of inbox placement, which the Terms disclaim.

07

Using another sequencer with EmailPal mailboxes

Mailboxes are hosted SMTP and IMAP, and credentials export as CSV in layouts for Smartlead, Instantly, Woodpecker, Salesforge and others. A team that already runs Instantly, Smartlead or lemlist can keep it and use EmailPal for domains, mailboxes and warming. Engage’s launch checks, pause rules and lead tracking only apply to mail Engage sends, so what you keep from EmailPal in that setup is the infrastructure.

08

Where a SaaS company should look at other tools

The comparison pages record these as of 5 October 2026. Instantly lists unlimited connected email accounts and a separate lead database of 450 million plus contacts, and is the more mature product. Smartlead lists unlimited connected mailboxes including Google and Outlook accounts, client workspaces, a deeper reply workflow, and pushes to CRM, Slack and Google Sheets. lemlist lists a lead database of 650 million plus contacts, multichannel steps (LinkedIn, SMS, calls) and CRM integrations with HubSpot, Salesforce and Pipedrive. EmailPal has none of those, and that is a fair reason to choose one of them.

EmailPal’s case is narrower: email-only outbound where mailboxes, warming, verification, sending, replies and pipeline sit in one account on one bill, and where the sequencer stops itself when bounces climb.