A business email address such as user@domain.com may be hosted on Google Workspace (G Suite) or Microsoft 365 (Office 365). You can quickly identify the recipient domain’s email provider by checking its MX records.
Open Windows Command Prompt and replace domain.com with the recipient’s domain.
nslookup -type=mx domain.com
Google Workspace
If the result contains the following MX record, it indicates that the domain uses Google Workspace (G Suite):
aspmx.l.google.com
Microsoft 365
If the result contains the following MX record, it indicates that the domain uses Microsoft 365 (Office 365):
domain.com.mail.protection.outlook.com
Verify Multiple Domains?
To check multiple recipient domains at once, run the following command in Command Prompt (CMD):
for %d in (domain1.com domain2.com domain3.com) do @echo. & echo ===== %d ===== & nslookup -type=mx %d
Replace domain1.com, domain2.com, and domain3.com with the domains you want to verify. You can also add more domains inside the brackets as required.
Note
A custom business email address does not necessarily indicate its actual email provider. Whether checking a single domain or multiple domains, reviewing the MX records helps confirm whether incoming email is handled by Google Workspace, Microsoft 365, or another mail service provider.
