How do they compare?
| Google Workspace | Microsoft 365 | |
|---|---|---|
| Rough cost | About $7–14 per mailbox a month | About $6–14 per mailbox a month |
| Owns the sending IP | Microsoft | |
| Places best into | Google-run companies | Microsoft-run companies |
| Main risk | Account suspension, especially new accounts sending volume fast1 | Tenant-level limits that restrict a whole organisation2 |
| DKIM | One TXT record at google._domainkey | Two CNAMEs, selector1 and selector23 |
| Verdict | Start here | Add second, matched to recipients |
Prices are rough 2026 ranges and vary by plan, country and billing; check current pricing before you budget.
Does provider matching really help?
One vendor’s data found same-provider sends (Google to Google, Microsoft to Microsoft) placed in the inbox 87–92% of the time, against 74–81% for cross-provider sends.2 Treat the exact figures as directional; the pattern matches what most senders see. Look up each prospect company’s MX record, or let your sending tool’s “provider matching” do it.
Why did Google suspend so many cold email mailboxes?
In October 2025, sending-tool vendors reported Google locking cold-email mailboxes, with free and discounted accounts (student domains, free Gmail) and shared infrastructure hit hardest; one vendor estimated about a quarter of its clients were affected.1 The lesson: real seats in your own tenant, never free, student or resold accounts, and a slow ramp on every new mailbox.
What about done-for-you inboxes and private SMTP?
Done-for-you inbox providers (roughly $3–10 per mailbox a month) are fast to launch and common at agency scale. Vet them first:
- Is it your own tenant, or shared with other customers?
- Are they real Google or Microsoft seats, or private SMTP?
- Can you move the mailboxes to another sending tool?
- What happens when a mailbox burns?
- What are the contract length and cancellation terms?
Private SMTP on your own IPs costs under $1 per mailbox but puts every mailbox on that IP at risk from one bad list. Leave it until you send at very high volume and have the expertise.
Common questions
Is Google Workspace or Microsoft 365 better for cold email?
Start on Google Workspace: it’s easy to set up, works with every sending tool and places well into Google-run inboxes. Add Microsoft 365 as your second provider to reach Microsoft-run companies and spread your risk.
Why do Google Workspace cold email accounts get suspended?
Common triggers are volume spikes above past sending, new accounts sending at scale immediately, high spam complaints and missing authentication. In late 2025 Google suspended many cold-email mailboxes, hitting free, discounted and shared accounts hardest.
What is provider matching in cold email?
Sending to Google-run companies from Google mailboxes and to Microsoft-run companies from Microsoft mailboxes. A company’s MX record shows which provider it uses, and most sending tools can match automatically.
Keep reading
Sources
- Salesforge: Google’s cold-email mailbox suspensions, October 2025 (vendor estimate). salesforge.beehiiv.com
- EmailBison: Google Workspace vs Microsoft 365 for cold email (vendor data). emailbison.com
- Microsoft Learn: Set up DKIM for Microsoft 365. learn.microsoft.com