Cold email infrastructure
Cold Email Infrastructure, Set Up in Minutes
Domains, Google and Microsoft mailboxes, SPF, DKIM and DMARC, and 1-click connection to your outreach tool: the whole sending stack, built and monitored for you.
- Outreach toolInstantly · Smartlead · 50+
- Mailboxes9 × Google & Microsoft
- Workspaces1 per domain, isolated
- Domainsgetnorthwind.com +2
- DNSSPF · DKIM · DMARC · MX
Jetmail at a glance
Infrastructure teams already run on
- mailboxes set up
- 1M+
- domains managed
- 330k+
- average setup time
- 5 min
- customer rating
- 4.8
How it fits together
What cold email infrastructure is made of
Five layers sit between your list and the inbox. Each one has to be right, for every domain, or deliverability suffers.
Step 1
Domains
Separate lookalike domains protect your main brand.
Step 2
Workspaces
One Google or Microsoft tenant per domain.
Step 3
Mailboxes
About 3 per domain, with names and photos.
Step 4
Authentication
SPF, DKIM, DMARC and MX published and monitored.
Step 5
Sequencer
Connected to Instantly, Smartlead or 50+ others.
| Layer | What it does | Do it yourself | With Jetmail |
|---|---|---|---|
| Domains | Separate sender reputation from your brand | Buy and configure one by one | Buy in the dashboard or bring your own |
| Workspaces | Isolate each domain's reputation | Often many domains in one tenant | One workspace per domain |
| Mailboxes | The accounts you send from | Create users and profiles by hand | Created in bulk with profile customization |
| SPF, DKIM, DMARC | Prove the mail is really from you | Hand-edit DNS for every domain | Published automatically, health-checked |
| Warmup | Build sending history | Wait 3–4 weeks per mailbox | Pre-warmed option |
| Monitoring | Catch blacklists and DNS drift | Separate tools | Built in (JetShield, DNS health checks) |
| Connection | Plug mailboxes into your sequencer | App passwords or manual OAuth | 1-click OAuth, 50+ tools |
Sizing
How much infrastructure your volume needs
Planning numbers: 30 cold emails per mailbox per day, 3 mailboxes per domain, 22 sending days a month.
Mailboxes needed by monthly cold email volume
Rounded up. Add 10–20% spare mailboxes so you can rest any that start to slip.
| 10K/mo | 16 |
|---|---|
| 30K/mo | 46 |
| 60K/mo | 91 |
| 100K/mo | 152 |
| 250K/mo | 379 |
| Emails / month | Mailboxes | Domains | Jetmail / month* |
|---|---|---|---|
| 10,000 | 16 | 6 | $60 |
| 30,000 | 46 | 16 | $151 |
| 60,000 | 91 | 31 | $297 |
| 100,000 | 152 | 51 | $455 |
| 250,000 | 379 | 127 | $1,136 |
*Standard mailboxes on the cheapest plan for that count, billed monthly. Domains are billed separately.
Providers
Cold email infrastructure providers compared
Published terms from each provider's own site, checked October 2026. Confirm on their site before buying.
| Jetmail | Zapmail | InboxKit | Icemail | Instantly | |
|---|---|---|---|---|---|
| Google mailboxes | $39/mo for 10 · $99/mo for 30 · $299/mo for 100 (extra $3.50–$3.00) | $39/mo for 10 · $99/mo for 30 · $299/mo for 100 (extra $3.50–$3.00) | $3.00/mailbox monthly, $2.50 billed annually; no minimum | $2.50/mailbox (promo; list $3.50) | $5/mailbox (done-for-you) |
| Microsoft mailboxes | Same price as Google | Offered; price not shown on site | Same price as Google | $2.50/mailbox | Not offered |
| Pre-warmed | Google & Microsoft: $39 for 3 · $149 for 12 · $339 for 30 first month, then $6–$8/mailbox | Offered; price not public. 12-month term, non-refundable, Zapmail-owned domains only | $6–$9/mailbox by warm age, plus a one-time domain transfer fee | $6/mailbox | $10/mailbox, Google only, batches of 5 |
| Setup time | 5 minutes on average | 5–10 minutes | Under 1 minute (first domain live in ~5) | 10–30 minutes | Minutes |
| Minimum order | 10 mailboxes (Starter) | 10 mailboxes (Starter) | None | Not stated | Paid Instantly plan required (from $47/mo) |
| Integrations | 50+ (Instantly, Smartlead, …) | 50+ (Instantly, Smartlead, Lemlist, …) | 24+ (Smartlead, Instantly, Apollo, …) | 30+ (Instantly, Smartlead, EmailBison, …) | Built into Instantly; needs a paid Instantly plan |
Deeper comparisons: Zapmail alternative · InboxKit alternative · Icemail alternative · Zapmail vs Instantly
Checklist
Cold email infrastructure setup checklist
- Buy 2–3 lookalike domains per brand and never send cold email from your main domain.
- Create 3 mailboxes per domain, each with a real name and profile photo.
- Publish SPF, DKIM and DMARC, plus MX so replies arrive. Check them with the SPF checker and DMARC checker.
- Forward each domain's website to your main site so prospects who visit see a real company.
- Warm up new mailboxes for 3–4 weeks, or start with pre-warmed inboxes.
- Cap each mailbox at about 30 cold emails a day and add mailboxes to grow.
- Monitor blacklists, bounce rate and spam complaints weekly.
Skip steps 1–5
Services
Cold email services: software, infrastructure or agency?
“Cold email service” can mean four different things. Most teams combine the first two; some hand everything to the third.
| Service | What you get | What you still need |
|---|---|---|
| Cold email software | Sequences, inbox rotation, follow-ups and reply handling. | Mailboxes, domains, a list and copy. |
| Cold email infrastructure | Domains, Google and Microsoft mailboxes, SPF, DKIM, DMARC and the connection to your tool. | Software, a list and copy. |
| Cold email agency | Strategy, lists, copy and sending run for you. | A clear offer and budget for a retainer. |
| Bulk email service (ESP / SMTP relay) | High-volume sending from shared or dedicated IPs. | Opted-in recipients. Check the provider's acceptable use policy before sending cold email. |
Bulk cold email service vs a dedicated SMTP server for bulk mailing
To be clear about what Jetmail is: it doesn't sell SMTP servers or bulk-mail IPs. Every Jetmail mailbox is a Google Workspace or Microsoft 365 account, so your mail leaves through Google's and Microsoft's own infrastructure, like any other business email. You get volume by adding mailboxes: 3,000 cold emails a day is about 100 mailboxes at 30 each (our planning number).
| Google & Microsoft mailboxes | Dedicated SMTP server | |
|---|---|---|
| Sending IPs | The provider's, managed by Google or Microsoft | Your own; you build and protect their reputation |
| Daily limits | 2,000 per Google user, 10,000 recipients per Microsoft user | Whatever your host allows |
| You set up | Domains and DNS (Jetmail does both) | Server, IP warmup, reverse DNS, TLS, blocklist monitoring |
| Connects to sequencers | OAuth, 1-click to 50+ tools | SMTP host, port and credentials |
| Built for | One-to-one outreach from named senders | High-volume opted-in marketing and transactional mail |
Choosing the sending tool to pair with your mailboxes? See the best cold email software. Would rather not run any of it yourself? Read what a cold email agency does and costs.
Domains
Google Workspace with multiple domains
Cold email needs several domains, and Google Workspace gives you two ways to run them.
| Setup | How it works | For cold email |
|---|---|---|
| One account, secondary domains | Up to 600 domains per Google Workspace account. Each secondary-domain user is a separate paid mailbox. | Works, but every domain sits in the same tenant. |
| One account, domain aliases | Up to 20 alias domains. Each user gets an extra address that delivers to the same inbox. | Poor fit: alias addresses share one inbox and one user's sending limit. |
| One workspace per domain | Each domain gets its own Google Workspace tenant and users. | Keeps each domain's reputation isolated. This is how Jetmail sets it up. |
3 mailboxes per domain, one workspace each
Google limits from Google Workspace Admin Help, checked October 2026.
Calculator
Price your infrastructure
- Mailboxes
- 46
- Domains
- 16
- Jetmail / mo
- $151
30 sends per mailbox per day, 3 mailboxes per domain, 22 sending days. Monthly billing, mailboxes only (domains are extra with every provider). Competitor prices from their public sites, checked Oct 2026.
Monthly cost for 46 mailboxes
- Jetmail$151
- Zapmail$151
- InboxKit$138
- Icemail$115
- Instantly$230
- Zapmail prices shown are first-year prices; its help center says Google Workspace plans rise to $49/$149/$449 after 12 months.
- InboxKit pre-warmed shown at its cheapest tier (2–4 weeks warmed), excluding one-time domain transfer fees.
- Icemail standard price is a limited-time promo ($3.50 list).
- Instantly accounts also need a paid Instantly sending plan (from $47/mo), not included above.
Get this quote by email
We'll send the breakdown plus a domain and DNS plan for 30,000 emails a month.
Get a free infrastructure plan for your volume
Tell us where to send it. We'll reply with mailbox, domain and DNS recommendations for your sending volume — or start right away and have mailboxes live in minutes.
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Or see pricing →Frequently asked questions
What is cold email infrastructure?
It's everything behind your outreach that isn't the copy: separate sending domains, the Google Workspace or Microsoft 365 mailboxes on them, DNS authentication (SPF, DKIM, DMARC, MX) and the connection to your sequencer. Good infrastructure keeps your main company domain out of the line of fire.
How much does cold email infrastructure cost?
Sending 30,000 cold emails a month takes about 46 mailboxes on 16 domains. On Jetmail that's $151 a month for the mailboxes, plus domain registration.
How many mailboxes and domains do I need?
Divide your monthly volume by 22 sending days and 30 emails per mailbox per day to get mailboxes, then divide by 3 mailboxes per domain. The table on this page does the math for common volumes.
Should I send cold email from my main domain?
No. Use separate lookalike domains (for example getacme.com or tryacme.co) so a spam complaint or blacklist hit never touches the domain your customers and invoices use.
Google Workspace or Microsoft 365 for cold email infrastructure?
Both work when they're set up properly. Many teams run a mix so mail comes from the same kind of provider their prospects use. Jetmail offers both at the same price, standard and pre-warmed.
What is private cold email infrastructure?
Mailboxes on official Google or Microsoft tenants that only you send from, rather than shared SMTP servers. Jetmail creates one workspace per domain, so one domain's reputation doesn't spill over onto your others.
Can I use a dedicated SMTP server for bulk cold email?
You can, but you take on the server's whole reputation: warming new IPs, reverse DNS, TLS and blocklist monitoring. Jetmail doesn't sell SMTP servers. Its mailboxes are Google Workspace and Microsoft 365 accounts, so mail goes out through Google's and Microsoft's own infrastructure, and you scale volume by adding mailboxes.
Can one Google Workspace account have multiple domains?
Yes. Google allows up to 600 domains per account, including up to 20 domain aliases. Secondary domains get their own paid users; aliases give existing users extra addresses that share one inbox. For cold email, Jetmail instead creates one workspace per domain, so each domain's reputation stays separate.
Who are the best cold email infrastructure providers?
Common options are Jetmail, Zapmail, InboxKit, Icemail and Instantly's done-for-you accounts. They differ most on pre-warmed pricing, minimum orders, Microsoft support and who owns the domains. The provider table on this page compares their published terms.