MX
MX records point to the hosts that receive mail for the domain and should resolve to valid A or AAAA records.
Tool
Mail servers and business email
Knowledge hub for mail servers, mail DNS, MX, SPF, DKIM, DMARC and secure business email.
A well configured mail platform is more than mailboxes. It combines MX, SPF, DKIM, DMARC, MTA-STS, TLS certificates, IP reputation, antispam controls and delivery monitoring.
Check MX, SPF and DMARC
Score the basic mail readiness of a domain.
DMARC tester
Review the domain policy and reporting setup.
MX glossary
Understand receiving mail hosts and priorities.
SPF glossary
List allowed mail senders for a domain.
DKIM glossary
Check how message signatures support trust.
MTA-STS and TLS-RPT
Secure SMTP transport and receive TLS reports.
Business mail servers: what should be checked?
Business email should have stable MX hosts, one coherent SPF policy, DKIM signing, DMARC reporting, MTA-STS where needed and encrypted access for SMTP, IMAP and webmail. Many deliverability problems start with small DNS mistakes left after a migration.
Mail DNS and security building blocks
SPF
SPF defines which servers and services may send email for the domain. Multiple SPF records or missing external senders cause common failures.
DKIM
DKIM signs messages with a domain key so recipients can verify that an authorized system signed the message.
DMARC
DMARC connects SPF and DKIM with the visible sender domain and defines what recipients should do with failing messages.
Recommended mail audit order
- Check receiving mail. Verify MX priorities, mail hosts and DNS records for every receiving host.
- Check sending sources. Make sure SPF includes the mail platform, CRM, helpdesk, newsletters and application servers.
- Check message signing. Verify DKIM selectors and confirm that every legitimate sender signs messages.
- Check domain policy. Review DMARC policy, reporting and SPF/DKIM alignment.
- Check secure transport. Verify MTA-STS, TLS-RPT and certificate consistency for MX hosts.
Typical business mail use cases
- Migration of company mail to a new provider or data center.
- Launching mailboxes in a business domain and checking MX records.
- Adding a newsletter, CRM, helpdesk or application sender to SPF and DMARC.
- Enabling MTA-STS and TLS-RPT for safer SMTP transport.
- Auditing a domain after spam, spoofing or deliverability problems.
FAQ: business mail servers
How should I use this DataHouse page?
Use it as a technical checklist and connect it with the relevant diagnostic tools before or after a production change.