ESDomain editorial team · Reviewed 1 November 2026
Plan mailboxes before editing DNS
Start by deciding which addresses you need, such as support, sales or an individual work address. Clarify which will be separate mailboxes and which will be aliases. Decide who will read each inbox and how that responsibility will move when the team changes, so business correspondence does not depend on one person.
The domain and email service are separate components. Register the name to the appropriate holder and obtain mailboxes from your chosen provider. Before activation, collect its setup instructions and locate the DNS service answering for your domain, particularly if external nameservers are in use. Keep those instructions with your service records.
MX, SPF, DKIM and DMARC have different jobs
MX routes incoming mail. SPF identifies authorised sending servers, while DKIM allows a message signature to be checked. DMARC adds policy and alignment checks for the sender’s domain. They are not interchangeable: adding MX alone does not complete authentication for messages sent from your accounts or other business tools.
Use the exact values supplied by your service. Do not copy another domain’s DKIM key or add separate SPF records for every tool without reviewing the combined configuration. List the systems sending mail on your behalf, including support, invoicing and forms, before deciding how the complete set should be authenticated.
Keep the previous service during migration
If email is already in use, inventory the existing accounts before changing records. Check whether messages, folders, contacts or filters must be migrated, and inform the people using those accounts. Do not delete an old mailbox simply because the new dashboard displays an address with the same name or login.
Schedule the change and test with external accounts. Send a message from the domain and reply to it. Check the expected inboxes, aliases and any error notices. Record the results and keep the previous service available during validation in line with the migration plan agreed with the people responsible.
Configure applications and check delivery
Mail applications need the provider’s connection details: server, port, encryption and username. SMTP is used to send messages and does not replace DNS records. Obtain the configuration for the particular account from the service dashboard instead of guessing the server hostname or copying settings from an unrelated website.
Correct DNS is one part of delivery, not a guarantee of always reaching the main inbox. Review authentication results, recipient information and message content too. If a test fails, keep the error message and the time it occurred so the support team can investigate the specific attempt more efficiently.