How Much Does Cold Email Infrastructure Cost? (2026)
Updated 17 October 2026 · 7 min read
Short answer
As of October 2026, the biggest cost in cold email infrastructure is mailbox seats: Google Workspace Business Starter lists at $7 per user per month on an annual plan ($8.40 on the monthly Flexible plan), and Microsoft 365 Business Basic lists at $7 per user per month with an annual commitment. Add sending domains (roughly one for every two or three mailboxes, about $13 a year each through ReplyDak), a sequencer such as Instantly or Smartlead (from about $39 to $47 a month on their entry plans, which include warmup), and your setup time. For 30 mailboxes, a do-it-yourself setup on Google Workspace list prices costs about $221–$263 a month before the sequencer; a managed provider like ReplyDak costs $87 a month for 30 mailboxes plus domains.
Cold email infrastructure has four cost lines: domains, mailboxes, warmup and a sequencer, plus the time it takes to set up DNS and keep things healthy. Prices below are US list prices as of October 2026. Taxes, local currency pricing and promotions can change what you actually pay, so check the official pricing pages linked in the sources.
The cost lines, one by one
| Cost line | Typical price (as of October 2026) | Notes |
|---|---|---|
| Sending domain | About $13/year per domain via ReplyDak (₹1,099/year) | Registrar prices vary; plan roughly 1 domain per 2–3 mailboxes |
| Google Workspace Business Starter | $7/user/month (annual plan) or $8.40 (Flexible, monthly) | Each cold mailbox is one paid user |
| Microsoft 365 Business Basic | $7/user/month (annual commitment) | Rose from $6 on July 1, 2026; month-to-month costs more |
| Warmup | Often included in your sequencer | Instantly and Smartlead plans include warmup; standalone tools charge per mailbox |
| Sequencer | Instantly Growth $47/month; Smartlead Base $39/month (monthly billing) | Both cheaper on annual billing; higher plans for more contacts |
| Your time | Hours per domain if done by hand | DNS records, DKIM keys, mailbox profiles, forwarding, troubleshooting |
How to estimate your own cost
- 1
Work out how many mailboxes you need
Divide your target daily cold sends by a conservative per-mailbox cap. For example, 900 cold emails a day at 30 per mailbox needs 30 mailboxes. See cold email sending limits.
- 2
Work out how many domains you need
Many teams put two or three mailboxes on each sending domain so a problem with one domain affects only a few mailboxes. 30 mailboxes at 3 per domain = 10 domains. See how many mailboxes per domain.
- 3
Price the mailboxes
Multiply mailboxes by the seat price: $7 (Google annual), $8.40 (Google Flexible) or $7 (Microsoft annual), or by a managed provider's per-mailbox price.
- 4
Add domains, sequencer and buffer
Convert yearly domain cost to monthly (÷ 12), add your sequencer plan, and keep 10–20% spare mailboxes so you can rest a domain without stopping. Or put your numbers into the cost calculator.
Worked example: 10, 30 and 100 mailboxes
Assumptions: 3 mailboxes per domain (rounded up), domains at $13/year, US list prices as of October 2026, sequencer excluded because it costs the same whichever infrastructure you choose. Monthly figures are rounded to the nearest dollar.
| Setup | 10 mailboxes (4 domains) | 30 mailboxes (10 domains) | 100 mailboxes (34 domains) |
|---|---|---|---|
| Domains per month | $4 | $11 | $37 |
| DIY Google Workspace, Flexible ($8.40) | $84 + $4 = $88 | $252 + $11 = $263 | $840 + $37 = $877 |
| DIY Google Workspace, annual ($7) | $70 + $4 = $74 | $210 + $11 = $221 | $700 + $37 = $737 |
| DIY Microsoft 365 Business Basic, annual ($7) | $70 + $4 = $74 | $210 + $11 = $221 | $700 + $37 = $737 |
| ReplyDak (mailboxes + warmup) | $35 + $4 = $39 | $87 + $11 = $98 | $269 + $37 = $306 |
Add your sequencer on top of every row, for example Smartlead Base at $39/month or Instantly Growth at $47/month on monthly billing (higher plans if you need more contacts). DIY rows also exclude your setup time and any standalone warmup tool if your sequencer does not include one. An annual Google or Microsoft plan also locks you into the seat count for the year, while ReplyDak bills monthly.
DIY vs. managed provider: what you are paying for
| Do it yourself | Managed provider (e.g. ReplyDak) | |
|---|---|---|
| Mailbox price | Full list price per seat | Lower per-mailbox price at volume |
| DNS setup | Manual, per domain | Automatic (MX, SPF, DKIM, DMARC, verification) |
| Warmup | Via sequencer or separate tool | Included, with automatic slow-down or pause |
| Domain forwarding | Manual | Automatic to your main site |
| Commitment | Annual plans are cheapest | Monthly billing |
| Control | Full admin control of your own tenant | Provider manages the setup for you |
DIY makes sense if you need only a handful of mailboxes, already have an admin who knows DNS, or need full control of the Workspace tenant. A managed provider is usually cheaper per mailbox beyond a small setup and saves the repetitive DNS and warmup work. Compare options in best cold email infrastructure providers.
ReplyDak pricing
| Plan | Mailboxes | Price per month | Per mailbox |
|---|---|---|---|
| Starter | 10 | $35 | $3.50 |
| Growth | 30 | $87 | $2.90 |
| Scale | 100 | $269 | $2.69 |
In India, mailboxes cost ₹289, ₹249 or ₹225 each on the same three tiers, billed in INR with a GST invoice. Billing is also available in USD or EUR. Domains are $13 / ₹1,099 per year. Mailboxes are Google Workspace today; Microsoft 365 is coming soon (waitlist). See pricing for current details.
See your exact monthly cost for any number of mailboxes.
Domains, DNS, Google Workspace mailboxes and warmup. From $2.69 per mailbox ($35 for 10).
FAQ
How much does Google Workspace cost per mailbox for cold email?
As of October 2026, Google Workspace Business Starter lists at $7 per user per month on an annual plan and $8.40 per user per month on the Flexible (monthly) plan in the US. Each cold email mailbox is one paid user.
How much does Microsoft 365 Business Basic cost?
As of October 2026, Microsoft lists Business Basic at $7 per user per month with an annual commitment, up from $6 after Microsoft's July 1, 2026 price update. Month-to-month billing costs more.
Do I need to pay separately for email warmup?
Often not. Instantly and Smartlead plans include warmup, and ReplyDak includes warmup with every mailbox. Standalone warmup tools usually charge per mailbox.
How many domains do I need for 100 mailboxes?
At two to three mailboxes per domain, roughly 34 to 50 domains. Fewer mailboxes per domain spreads risk further but costs more in domains.
Is a managed cold email provider cheaper than Google Workspace directly?
At volume, often yes. In the 30-mailbox example above, Google Workspace at list price costs $210–$252 a month for seats, while ReplyDak costs $87 a month for 30 mailboxes including warmup. Domains and the sequencer cost the same either way.