B2B Email SaaS โ€” Master Cheatsheet 2026
Master Cheatsheet ยท 2026 Edition

B2B Email SaaS
Cold Outreach vs. Permission Marketing

A complete guide to Instantly.ai, Apollo.io, Woodpecker, Mailchimp, and Constant Contact โ€” pricing, features, compliance, and when to use each.

5 Platforms Compared Pricing Verified May 2026 B2B Cold Outreach Focus

The fundamental divide

These are not interchangeable tools. Using the wrong category for your use case risks account suspension or wasted spend.

Category A
Cold B2B Outreach

Send to non-opted-in prospects. Built for sales teams generating new pipeline from scratch. Sequences, warmup, inbox rotation, and deliverability tools are core concerns.

Instantly.ai ยท Apollo.io ยท Woodpecker
Category B
Permission-Based Marketing

Send only to opted-in subscribers. Built for nurturing existing audiences โ€” newsletters, promotions, and automations to people who asked to hear from you.

Mailchimp ยท Constant Contact

Pricing snapshot

All prices verified May 2026. Annual billing shown where available. Real-world costs often run higher โ€” see the full table below.

Instantly.ai
$37.60/mo (annual)
ModelEmail volume / mo
Growth$37.60โ€“$47/mo
Hypergrowth$77.60โ€“$97/mo
Light Speed$358/mo
Full stack min.~$124/mo
Free planโœ— (14-day trial)
Apollo.io
$49/user/mo (annual)
ModelPer seat + credits
Basic$49โ€“$59/user
Professional$79โ€“$99/user
Organization$119โ€“$149/user
Real cost$150โ€“$400/user
Free planโœ“ (very limited)
Woodpecker
$24/mo (annual)
ModelProspects contacted
Starter (500/mo)$24โ€“$29/mo
Growth (10k/mo)~$126/mo
Scale (100k/mo)~$903/mo
LinkedIn add-on+$29/acct/mo
Free planโœ— (7-day trial)
Mailchimp
$13/mo (500 contacts)
ModelContacts in list
Essentials$13/mo
Standard~$20/mo
Premium~$350+/mo
Free planโœ“ (250 contacts)
Cold emailโœ— Prohibited
Constant Contact
$12/mo (500 contacts)
ModelContacts in list
Lite$12/mo
Standard$35/mo
Premium$80/mo
Free planโœ— (14-day trial)
Cold emailโœ— Prohibited

Full feature comparison

Instantly, Apollo, and Woodpecker vs. Mailchimp and Constant Contact across every major dimension.

Feature Instantly.ai Apollo.io Woodpecker Mailchimp Constant Contact
โšก Fundamentals
Primary use case Cold email at scale Sales intelligence + outreach Cold email, agency outreach Newsletter & campaign marketing SMB email + event marketing
Who it’s built for SDRs, growth teams Sales teams, RevOps Agencies, B2B sales Marketers, ecommerce, creators SMBs, nonprofits, event orgs
Recipient type Non-opted-in prospects Non-opted-in prospects Non-opted-in prospects Opted-in subscribers only Opted-in subscribers only
Email style 1:1 personalised sequences 1:1 personalised sequences 1:1 personalised sequences Broadcast campaigns + automation Broadcast campaigns + automation
G2 rating โ˜… 4.3 / 5 โ˜… 4.7 / 5 (9,400+ reviews) โ˜… 4.3 / 5 โ˜… 4.5 / 5 โ˜… 4.0 / 5
๐Ÿ’ฐ Pricing model
Pricing unit Email volume / moNot per seat Per seat + creditsCosts multiply with team Prospects contactedNot emails sent Contacts in listScales steeply Contacts in list317% jump at 1k contacts
Team members โœ“ Unlimited (no per-seat) โœ— Per seat โ€” costs multiply โœ“ Unlimited (no per-seat) ~ Limited on lower tiers ~ Up to 10 on top plans
Overage handling Hard send cap โ€” stops sending Credit overages $0.20+ each Must delete prospects or upgrade Charged for extra sends $0.002 per email over limit
Hidden cost risk High โ€” 3 separate products High โ€” credit burn + seat cost Medium โ€” LinkedIn add-ons High โ€” steep list-size tiers Very high โ€” aggressive scaling
Annual discount ~20% ~20% ~15โ€“20% โ€” 15% (nonprofits 30%)
โœ‰๏ธ Email sending features
Email warmup โœ“ Included all plans โœ— Not included โœ“ Included all plans โœ— Uses own shared infra โœ— Uses own shared infra
Unlimited email accounts โœ“ All plans โœ— Plan-limited โœ“ All plans N/A โ€” single sender N/A โ€” single sender
Inbox rotation โœ“ โœ— โœ“ โœ— โœ—
Sequences / drip โœ“ Core feature โœ“ Core feature โœ“ Core feature ~ Automations (Standard+) ~ Automations (Standard+)
A/B testing ~ Hypergrowth+ only โœ“ Basic+ tier โœ“ All paid plans โœ“ Standard+ โœ— Premium only
Deliverability monitoring ~ Analytics; inbox placement add-on ~ Basic reporting โœ“ Built-in, all plans ~ Basic reporting ~ Basic reporting
Drag-and-drop templates โœ— Plain-text focused ~ Basic ~ Basic โœ“ Extensive library โœ“ Extensive library
AI writing / personalisation โœ“ Icebreakers, dynamic variables โœ“ Professional+ AI assist ~ Basic personalisation โœ“ AI content recommendations ~ Limited AI tools
Segmentation ~ Basic filters โœ“ Advanced ~ Basic โœ“ Predictive segmentation โœ“ Advanced (Standard+)
Unified inbox โœ“ Hypergrowth+ โœ“ โœ“ N/A N/A
๐Ÿ” Lead data & prospecting
Built-in lead database ~ Instantly Credits add-on$47โ€“$169/mo separate โœ“ 210M+ contacts includedCore product differentiator โœ— Bring your own listLead finder add-on available โœ— Bring your own list โœ— Bring your own list
Contact enrichment ~ Via Lead Finder credits โœ“ Included (uses credits) โœ— Limited natively โœ— โœ—
Buying intent data โœ— โœ“ Basic+ tier โœ— โœ— โœ—
Email verification โœ“ Catch-all verification โœ“ โœ“ Catch-all included ~ Basic bounce handling ~ Basic bounce handling
๐Ÿ”— CRM & integrations
Native CRM ~ CRM plan add-on ($47/mo) โœ“ Built-in pipeline & deals โœ— External CRM via integrations ~ Basic audience/contact mgmt ~ Basic contact management
Key integrations HubSpot, Salesforce, Pipedrive, Zapier HubSpot, Salesforce, native CRM HubSpot, Pipedrive, Salesforce, Zapier Shopify, WooCommerce, Canva, 300+ apps Shopify, Eventbrite, 300+ apps
Agency / white-label ~ DFY add-on โœ— โœ“ Full white-label agency panel โœ— โœ—
Multichannel (LinkedIn, SMS, calls) ~ Multi-channel via CRM plan โœ“ LinkedIn + dialer (Pro+) ~ LinkedIn add-on $29/acct/mo ~ Social posting + SMS add-on โœ“ Social posting + SMS + events
Landing pages / forms โœ— ~ Basic โœ— โœ“ Included โœ“ Included
Event registration โœ— โœ— โœ— โœ— โœ“ Native โ€” unique feature
๐Ÿ›ก๏ธ Compliance & legal
Cold email permitted? โœ“ Core purpose โœ“ Core purpose โœ“ Core purpose โœ— Prohibited in ToS โœ— Prohibited in ToS
Compliance framework CAN-SPAM B2B compliant CAN-SPAM B2B compliant CAN-SPAM B2B compliant Requires GDPR/CAN-SPAM opt-in Requires GDPR/CAN-SPAM opt-in
Cold email account risk None โ€” built for it None โ€” built for it None โ€” built for it Account suspension Account suspension
Sender reputation tools Warmup, rotation, DKIM/SPF setup DKIM/SPF, limited warmup tools Warmup, deliverability monitor, DKIM/SPF Shared sending infrastructure Shared sending infrastructure

Decision guide โ€” which tool for which scenario?

Match your situation to the right platform before committing.

Your situation Best choice Why
You have a lead list and need high-volume cold email from multiple domains Instantly.ai Unlimited inboxes, built-in warmup, and volume-based pricing (not per seat) make it the best pure cold-send engine
You need to find B2B leads AND reach out to them in one platform Apollo.io 210M+ contact database with intent signals, sequences, LinkedIn, and a native CRM โ€” all under one login
You’re an agency managing multiple client outreach campaigns Woodpecker White-label agency panel, deliverability monitoring on all plans, and prospect-based pricing that doesn’t penalise team size
You want to nurture an existing opted-in email list with beautiful branded campaigns Mailchimp Rich template library, ecommerce integrations, predictive segmentation, and automation journeys built for subscriber marketing
You run events, are a nonprofit, or a local/retail SMB with a small opted-in list Constant Contact Native event registration with payment processing is unique in this category. 30% nonprofit discount and a simple editor for non-technical users
You have a small budget and just want to test cold email outreach solo Woodpecker or Instantly.ai Woodpecker’s $24/mo starter is the cheapest entry. Instantly’s $47/mo gets you unlimited inboxes if deliverability is a priority
You need phone / mobile data in addition to email for outbound calling Apollo.io Only Apollo includes mobile credits and a built-in sales dialer. The others are email-only tools
You want to run both cold outreach AND newsletter campaigns Two tools: Instantly + Mailchimp These are genuinely different tools for different channels. Stack them โ€” don’t try to make one do the other’s job

Key insights & watch-outs

The things most pricing pages won’t tell you.

Instantly.ai โ€” Modular cost trap
The advertised $37/mo covers only the Outreach module. Add Lead Finder and CRM and the minimum full-stack spend is ~$124/mo. Most users end up paying $180โ€“$241/mo for a complete setup.
Apollo.io โ€” Credit burn is the real cost
At $49/user on paper, active SDR teams typically spend $150โ€“$400/user/month once mobile credit overages kick in. Phone numbers cost 8ร— more credits than emails. Forecast credit consumption before signing.
Woodpecker โ€” Prospect โ‰  email
Woodpecker limits new prospects added per month, not emails sent. Follow-up emails to existing prospects don’t count. Great for multi-step sequences but you must delete old contacts to add new ones at lower tiers.
Mailchimp โ€” Free plan gutted in 2026
The free plan was cut to 250 contacts and 500 sends/mo in January 2026 (down from 500/1,000). Most small businesses outgrow it within weeks. Budget for Essentials ($13/mo+) from the start.
Constant Contact โ€” Steepest list scaling
Going from 500 to 1,000 contacts on the Lite plan jumps from $12 to $50 โ€” a 317% price increase for doubling your list. Constantly recalculate your cost as your subscriber base grows.
The compliance rule everyone forgets
Mailchimp and Constant Contact will suspend your account for sending to purchased or cold lists โ€” it violates their ToS. Cold outreach requires a dedicated tool. Never use permission-based platforms for prospecting.

Platform verdicts

The one-line summary for each tool.

Instantly.ai
Volume cold email engine
The go-to for teams sending at scale from multiple domains. Unlimited inboxes + warmup is genuinely hard to beat. Real costs run 3ร— the headline price once you add leads and CRM.
Apollo.io
All-in-one sales intelligence
Best when you need leads AND outreach in one place. The 210M+ database with intent signals is the real differentiator. Watch the credit system โ€” it’s the #1 budget surprise.
Woodpecker
Agency & deliverability specialist
Lowest true starting price, white-label agency panel, and the best built-in deliverability monitoring of the three. Scales steeply at high prospect volumes.
Mailchimp
The brand marketing workhorse
Rich templates, ecommerce automations, and predictive segmentation make it the default for subscriber-based email marketing. Not for cold outreach โ€” full stop.
Constant Contact
SMB & event marketing specialist
Unique native event registration with payment processing. Best suited for nonprofits, local businesses, and community orgs. Most aggressively priced as your list grows.