A business email address that uses your own domain does more than look professional. It keeps customer conversations under your control, makes staff changes easier to manage and helps protect your reputation when email is configured correctly. To configure Microsoft 365 email, you need to connect the service to your domain, create mailboxes and make sure the right DNS records are in place.
The process is manageable for small businesses, but a missed record or an old setting left behind can cause messages to disappear, land in junk folders or continue arriving at a previous provider. Taking a careful, staged approach avoids disruption.
What you need before you start
Have access to the Microsoft 365 admin centre and to the DNS controls for your domain name. DNS is the set of records that tells the internet where to find your website and email. Your domain may be registered with one company and hosted with another, so check where its DNS zone is actually managed before making changes.
You should also know whether you are moving from an existing email provider. If you are, do not cancel the old service at the start. Keep it active until mailboxes have been created, historic messages have been moved where needed and you have confirmed that new messages are arriving in Microsoft 365.
Before changing anything, make a note of your current MX, SPF and autodiscover records. This is particularly useful if your business uses website contact forms, scanners, accounting software or other devices that send email. These services may need their outgoing mail settings updated after the change.
Add and verify your domain in Microsoft 365
In the Microsoft 365 admin centre, add the domain you want to use for email, such as yourbusiness.co.uk. Microsoft will provide a verification record, normally a TXT record, to add to your DNS zone. This proves that you control the domain and prevents someone else from attaching it to their Microsoft 365 account.
Copy the record exactly as supplied. Small errors matter here: an extra space, a missing character or adding the record to the wrong DNS provider will prevent verification. DNS changes can appear quickly, but they may take several hours to become visible everywhere.
Once Microsoft confirms ownership, you can make the domain the default for new users if appropriate. A sole trader may only need one address, while a growing organisation may want to create accounts for named staff and separate shared addresses for enquiries, accounts or bookings.
Create user mailboxes and shared addresses
Each person who needs to sign in, send and receive their own email, and use Microsoft 365 applications needs an appropriate licence. Create the user with their full name and business email address, then assign the licence that includes Exchange Online email.
Set a strong temporary password and require the user to change it when they first sign in. Multi-factor authentication should be enabled for every account. It adds a second check when signing in and offers valuable protection if a password is guessed, reused or exposed elsewhere.
Shared mailboxes work well for addresses such as info@, sales@ or support@. They allow several authorised people to view and reply to the same messages without sharing a password. Give access only to the staff who need it, and review those permissions when someone changes role or leaves the business.
Configure Microsoft 365 email DNS records
This is the part that determines where messages are delivered and whether other email providers trust messages sent from your domain. Microsoft presents the records needed for your specific setup in the admin centre. Use those values rather than copying an old example from elsewhere, as settings can differ between tenants.
MX record: where incoming email goes
Your MX record directs incoming email to Microsoft 365. Replace the existing MX record only when the new mailboxes are ready to receive messages. Leaving two conflicting MX records, or retaining an old provider at a higher priority, can produce unpredictable delivery.
Most domains should have one Microsoft 365 MX record once the move is complete. If you use a specialist email security gateway, the route may be different. In that case, follow the gateway provider’s guidance rather than replacing records blindly.
SPF record: who can send for your domain
An SPF record tells receiving mail systems which servers are allowed to send email using your domain. Microsoft 365 provides an SPF value that normally includes its sending service. If your website, newsletter platform or other system also sends as your domain, it must be included correctly too.
There must be only one SPF TXT record for a domain. Adding a second one is a common mistake and can weaken delivery rather than improve it. Combine authorised senders into a single record, and avoid making it overly broad simply to stop an error message.
Autodiscover and other service records
Autodiscover helps Outlook and compatible apps find the correct mailbox settings automatically. Microsoft may also request CNAME or TXT records for device management, Teams or other services, depending on your subscription.
Add the records required for the services you use, but do not remove website-related records unless you are certain what they do. Your A and CNAME records for the website are separate from email routing in most cases. Email changes should not take a working site offline, provided the correct DNS records are left in place.
Protect sending reputation with DKIM and DMARC
Receiving providers increasingly check more than the basic MX record. DKIM and DMARC help show that messages claiming to come from your domain are legitimate. They reduce the risk of spoofing and can improve confidence in your email delivery.
DKIM adds a signed digital identifier to outgoing messages. In Microsoft 365, you first add the two DKIM CNAME records supplied for the domain, then enable DKIM in the security settings. Do not enable it before the records have propagated, as the checks will fail.
DMARC tells receiving servers how to handle messages that fail authentication checks and where to send reports. Start with a monitoring policy so you can see whether legitimate services are sending on your behalf. Once you have checked the reports and corrected any overlooked senders, a stricter policy can provide stronger protection. The right pace depends on how many third-party systems your business uses.
Move existing mail without losing messages
If staff have years of email at another provider, plan the migration before switching the MX record. For a small number of mailboxes, email can often be copied using an appropriate migration method or exported from a desktop mail application. Larger moves benefit from a scheduled migration that transfers messages in stages.
Choose a quiet period for the final switch, particularly if your organisation receives orders, appointment requests or urgent client correspondence by email. Tell staff what will change, give them sign-in instructions and ensure they know how to use webmail if their desktop Outlook setup is not ready yet.
Keep the former email account available for a short overlap period. Check both systems during that time, then confirm that new messages are consistently reaching Microsoft 365 before retiring the previous service. This also gives you time to update any devices or applications still using old SMTP settings.
Test the setup from outside your business
Do not rely only on an email sent from one new mailbox to another. Send a test message to and from an external address, such as a personal account. Check that it arrives, that replies return to the right mailbox and that it does not appear with a warning or in the junk folder.
Test each address customers use, including shared mailboxes and aliases. Then check Outlook on the web and any desktop or mobile devices used by staff. If messages are not arriving, inspect the MX record first. If messages are arriving in junk folders, review SPF, DKIM and DMARC, along with the content and sending behaviour of the message itself.
Keep access and email settings under review
Email setup is not a one-off administrative job. Remove access promptly when a staff member leaves, keep recovery details current and review forwarding rules periodically. Unexpected forwarding rules can be a sign that an account has been compromised.
It is also sensible to document who manages your domain, DNS and Microsoft 365 tenancy. When these essentials are spread across different logins with no clear ownership, a simple renewal or staff change can become an avoidable interruption.
If you would prefer help with the domain side of the change, Pac Web Hosting can provide practical guidance on DNS and hosting settings while you retain control of your business email. A properly planned setup gives your customers a dependable address to contact and gives your team a service they can rely on each working day.
