DELIVERABILITY
Microsoft or Google inboxes in 2027: check what your list runs on first
An address ending in a company domain tells you nothing about who hosts its mail. The MX record does, and reading it takes minutes.
To choose between Microsoft and Google inboxes, look up who hosts the mail for a sample of the domains on your list, then count. The address alone will not tell you, because a company domain can sit on either. The MX record will.
How do you find out what a list runs on?
- Export the unique domains from your list, leaving out personal addresses such as gmail.com and outlook.com. Count those separately.
- Take a random sample of 100 domains. Sorted lists skew towards one sector or one letter.
- Run them through the DNS Records Checker, 25 domains at a time, and export the CSV.
- Count each domain by what its MX record points at.
| MX record contains | Mail is hosted by |
|---|---|
| google.com or googlemail.com | |
| mail.protection.outlook.com | Microsoft 365 |
| A security gateway, such as Proofpoint or Mimecast | Unknown: the gateway hides the provider behind it |
| Anything else | Another host or the company’s own server |
How do you read the result?
| What your sample shows | What usually follows |
|---|---|
| Mostly Google | This is the case people choose Google for. Compare the price at your volume, then decide. |
| Mostly Microsoft | Nothing argues for paying Google’s higher cost per send. Start with Microsoft. |
| Mixed, or mostly gateways | Let price and volume decide. Microsoft costs less per send. |
This tells you what your recipients run on. It does not tell you which provider will land better. We have not measured a placement difference between them and do not claim one. Our published bounce and reply figures all come from Microsoft 365 sending, so there is no Google figure to compare.
What does each choice cost?
Microsoft is 100 inboxes on a domain for $30 a month, 300 sends a day. Google is $3 per inbox, up to 3 on a domain, 45 sends a day, with full admin access. That makes Google twice the price per email of daily capacity: $0.20 against $0.10. The totals at real volumes are in the cold email infrastructure budget.
Can you run both?
Yes. They are separate products on separate domains, and one sequencer can hold both. A mixed list can start on one and add the other later, which is often cleaner than guessing at the split in advance.
When is the list not the deciding factor?
When volume drives the decision. Microsoft reaches volume by filling a domain and Google by adding domains, so a high daily target on Google means a long list of domains to buy and warm up. For a platform comparison rather than a list-based one, read Microsoft 365 vs Google Workspace for cold email.
Frequently asked questions
How do I know if a company uses Google or Microsoft for email?
Look up the MX record for its domain. A record containing google.com means Google, and mail.protection.outlook.com means Microsoft 365. A security gateway hides the provider behind it.
Should I match my sending provider to my list?
Many senders choose Google when a list is mostly Gmail, and that is a fair reason to want the mail to come from Google. We have not measured a placement difference between the two and do not claim one.
How many domains do I need to sample?
A random sample of 100 is enough to see the broad split. You are looking for a clear majority or a mix, not an exact percentage.
Infrastructure without the setup
100 Microsoft 365 inboxes on one domain for $30, with SPF, DKIM and DMARC configured and verified before handover. Live in 24 to 48 hours.
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