Can I use a subdomain for email on my domain?
How subdomain mail works
MX records can point to a name at any level of your domain, so a subdomain can receive mail if you create the right records. The sending side also needs SPF, DKIM, and DMARC records that cover the domain used in the sender address, so plan those together.
Some teams use a subdomain to separate marketing mail from business mail. This can help protect the main domain's reputation if one stream runs into spam issues.
- MX records can be set on a subdomain
- SPF and DKIM must cover the sending domain
- Separating mail streams can protect the main domain
Keeping it simple
For most small sites, the bare domain is easier to manage and matches what users expect. Use a subdomain only when you have a clear reason, such as separating bulk mail from personal mail.
Whichever path you choose, test by sending a message and checking the headers for passing SPF and DKIM results.
Subdomain mail can also complicate DMARC reporting, so decide which domain should receive reports. Keep your records organized in a spreadsheet to avoid confusion later. Test sending and receiving from each address you plan to use.
Common mistakes
- Creating an MX record on the subdomain but forgetting SPF and DKIM for it.
- Using a subdomain for email without telling users which address to use.
