Cold Email Infrastructure Provider: How to Choose

At minimum the purchase should cover:

1. Sending domains separate from your primary company domain.
2. Mailboxes on a named platform you can identify.
3. MX, SPF, DKIM, and DMARC on those domains.
4. A path to warm up and ramp without inventing your own DNS project every week.
5. Credentials or a sign in path your sequencer can use.

If those five are fuzzy in the quote, keep shopping.

1. Is the platform named?

Official Google Workspace, Microsoft 365, private SMTP, or a shared pool are different products. Prefer a written answer for each mailbox type you will buy. Vague "inboxes" usually means shared infrastructure. ColdMail's category choice is official Google Workspace only, with no shared SMTP pool and no Microsoft 365 in the product.

2. Whose domains, and can you keep them?

Bring your own domains when you can. If you buy through the provider, confirm registration sits in an account you control and that you can move the domains later. Domains carry months of reputation; losing them resets the clock.

3. Do you get real admin access?

You need password resets, 2FA enforcement, sign in history, and the ability to remove a mailbox the day someone leaves. Without an Admin console (or equivalent), every incident is a support ticket.

4. Is authentication finished before volume?

Google's public sender guidelines require SPF or DKIM for all senders to Gmail, with spam rates in Postmaster Tools below 0.3 percent; senders over 5,000 messages per day to Gmail also need SPF, DKIM, and DMARC. The provider should publish those records and you should be able to verify them yourself on a test email. Automation is useful. Blind trust without visible records is not. See SPF DKIM DMARC Setup for Cold Email.

5. Is there a density and capacity plan?

Common operator practice is two or three mailboxes per domain, with a soft ceiling around five, and roughly 20 to 40 cold sends per warmed mailbox per day including follow ups. Capacity comes from more domains, not from packing one domain or climbing toward Google's published per user ceiling (sending limits page). See How Many Mailboxes Per Domain for Cold Email.

6. How does sequencer handoff work?

Mailboxes should be ready to connect in Instantly and Smartlead using the methods those tools support, typically signing in with Google (OAuth) or IMAP and SMTP with app passwords. The same idea applies to n8n and other tools that speak IMAP or Google APIs. Ask how any handoff works and check the sequencer docs before you rely on a custom connector story.

7. Can agencies separate clients?

If you sell outbound for more than one brand, ask whether multiple organizations or clearly separated pools exist on the plan you are buying. One client's pause should not touch another client's mailboxes. Separation is plan dependent at many providers, including ColdMail.

On shared SMTP, mail leaves through provider run servers and often shared IP ranges. You inherit neighbours you cannot see. On official Google Workspace with dedicated domains, mail leaves through Google's infrastructure from an organization you control, and the reputation that matters most is the one your domains build. Shared SMTP is usually faster to start. Workspace gives you a known platform and admin control. Neither removes the need for clean lists and sane caps. See Dedicated Google Workspace vs Shared Cold Email Infra and Dedicated Google Workspace Versus Shared Cold Email Infra.

• The platform is unnamed.
• Domains are locked to the vendor with no export path.
• You cannot open an Admin console.
• DNS is "handled" with no records you can inspect.
• The plan assumes one mailbox will carry hundreds of cold sends a day.
• Marketing leads with a placement percentage or a timed setup promise you cannot verify.
• Warmup is sold as a shield that forgives bad lists.

1. Write must haves: Google only or multi provider, BYO domains, admin access, agency separation.
2. Answer the seven questions for each vendor in a sheet.
3. Pilot a small pool connected with documented sequencer methods.
4. Judge the pilot on auth pass rate, setup friction you measured, and human replies, not on open rate alone.

A pilot should prove control, not volume.

• Two or three dedicated domains, authenticated end to end.
• A handful of mailboxes under the daily caps you actually intend to keep.
• Connection into the sequencer you already run, using documented methods only.
• One week of sending to a clean, verified segment while you watch replies, bounces, and complaints.

If the provider cannot support that small shape cleanly, they will not support a larger shape either. Scaling a broken pilot only spreads the break. See Deliverability Dropped After You Scaled: What Changed.

Infrastructure outlives the first campaign. Before you commit, write down:

• Who owns the domain registrar login.
• Who is the Super Admin on each Google organization.
• What happens to domains and mailboxes if you leave the provider.
• How long DNS and mailbox export take in a normal offboarding.

Providers that cannot answer those questions are renting you a dead end. Domains with clean history are an asset; treat them that way in the contract conversation even when this article stays away from legal templates.

Warmup belongs on the checklist as an optional, adjustable step. It helps new mailboxes build sending history. It does not repair a dirty list, missing DMARC, or a daily cap that looks like a blast. Prefer providers that let you turn warmup on or off and that never substitute a warmup badge for health metrics you can read per domain.

ColdMail is a cold email infrastructure provider built on official Google Workspace. It provisions mailboxes on dedicated domains you bring or buy through ColdMail, publishes SPF, DKIM, DMARC, and MX automatically, and gives you an official admin panel per domain with 2FA plus provider health indicators for Gmail, Outlook, and Yahoo. AI warmup is available as an optional add on; see coldmail.app for current add on pricing. Multiple organizations are available on supporting plans.

ColdMail is not a sequencer. Mailboxes are ready to connect in Instantly and Smartlead using the methods those tools support, and they work with n8n and other tools. There is no shared SMTP pool in the product.

If the checklist points at dedicated official Workspace, set up your mailboxes at coldmail.app, or Book a Strategy Call to map domains and caps to your volume.