What is an email subdomain?
A subdomain is a name added in front of your root domain, separated by a dot. If your root domain is example.com, names such as mail.example.com, notify.example.com, and billing.example.com are subdomains.
A subdomain can have its own email addresses and its own sending or receiving setup. For example, adding notify.example.com creates addresses such as [email protected]—not [email protected].
MailLogic can treat the subdomain as its own email domain while still recognizing its relationship to the root domain.
Use MailLogic alongside an existing email provider
A subdomain is useful when your root domain already receives email somewhere else and you do not want to replace that setup.
For example, example.com can continue using Google Workspace or Microsoft 365 for ordinary staff mail, while notify.example.com uses MailLogic for SMTP, API, Batch Send, or forwarding.
Because the two names have separate DNS records, changing the mail routing for notify.example.com does not require replacing the MX records for example.com.
[email protected]
Keep human business conversations with your existing mailbox provider.
Should you use the root domain or a subdomain?
Your root domain is usually the natural choice for your main business identity. A subdomain is often a cleaner choice for app-generated or transactional email.
| Use case | Usually start with | Why |
|---|---|---|
| Messages to customers, partners, contractors, or clients that people compose or review | Root domain | The address stays close to your primary business identity. |
| Receipts, invoices, password resets, login alerts, notifications, or system updates | Subdomain | Automated mail gets a clearer operational boundary. |
| Your root domain already uses Google Workspace, Microsoft 365, or another provider | Subdomain | You can add MailLogic without replacing the root domain's receiving setup. |
These are starting points, not protocol requirements. Choose the address structure that will make sense to recipients and remain manageable for your team.
Common email-subdomain patterns
The name before your root domain can describe the purpose of the messages:
notify.example.comfor alerts and product notifications.billing.example.comfor invoices, receipts, and account notices.mail.example.comfor a general separate email environment.
A useful name should be recognizable, durable, and broad enough that you will not need a new domain setup for every small message category.
DNS records for a subdomain
example.com and notify.example.com are separate email setups. MX records for receiving and SPF or DKIM records for sending must be published at the names required for the subdomain setup.
DMARC has an inheritance rule. If a subdomain does not publish its own DMARC record, the organizational domain's policy can apply to it. The root-domain record can use an sp value for subdomains; otherwise its p value is used. A subdomain can publish its own DMARC record when it needs an explicit policy.
Do not assume that adding one DNS record automatically configures every related name. Check the exact host name for each record and account for DMARC inheritance when deciding whether the subdomain needs an override.
MailLogic's domain setup instructions show the required host names and values for the domain or subdomain you added. Follow those displayed values rather than adapting another domain's records by guesswork.
For an explanation of the authentication records, see SPF, DKIM, and DMARC explained.
What reputation separation does—and does not—do
Automated mail can have different volume, formatting, bounce patterns, and recipient behavior from ordinary human email. A subdomain creates a clearer operational boundary between those streams.
That boundary helps you manage the two uses separately, but it does not make reputation risk disappear. Providers can evaluate multiple signals, including relationships between a subdomain and its organizational domain.
Authentication, list quality, sending behavior, and message relevance still matter regardless of which domain level you choose.
Adding a subdomain to MailLogic
Add the complete subdomain you intend to use, such as notify.example.com. MailLogic recognizes that it is a subdomain, understands its relationship to the root domain, and adjusts the DNS setup instructions accordingly.
Treat it as its own email domain when creating addresses and checking readiness. An address created for the subdomain will include that subdomain in the part after the @ symbol.