Email Setup Wizard

Microsoft 365 + IONOS

Set up Microsoft 365 email on IONOS

The records Microsoft 365 needs, written with the field names IONOS uses (Host name, Points to, Value, Alias), in the order to add them.

  • 6 steps
  • 7 DNS records
  • Sources checked October 21, 2026

Before you start

  1. Have your Microsoft 365 account ready. Some values are unique to your account and come from the Microsoft 365 admin center.
  2. Open DNS at IONOS: Sign in at login.ionos.com, select Menu, then Domains and SSL. Under Actions for your domain, select the gear icon, then DNS.
  3. Keep both tabs open and add the records below one at a time.

Records to add

Copy each value with the button next to it. Rows marked “Copy from Microsoft 365 admin center” are unique to your account.

Domain verification Proves you own the domain Type TXT Host name Leave empty Value Copy from Microsoft 365 admin center Looks like: MS=ms followed by digits Priority n/a TTL 3600 (1 h)
MX records Where incoming email goes Type MX Host name @ Value Copy from Microsoft 365 admin center Looks like: <your MX token>.mail.protection.outlook.com, or for domains set up on Microsoft's newer DNSSEC infrastructure <your MX token>.<subdomain>.mx.microsoft Priority 0 TTL 3600 (1 h)
SPF record Which servers may send as you Type TXT Host name Leave empty Value v=spf1 include:spf.protection.outlook.com -all Priority n/a TTL 3600 (1 h)
DKIM A signature on every message · recommended Type CNAME Host name selector1._domainkey Value Copy from Microsoft 365 admin center Looks like: selector1-yourdomain-com._domainkey.<your onmicrosoft prefix>.<letter>-v1.dkim.mail.microsoft (older domains: selector1-yourdomain-com._domainkey.<prefix>.onmicrosoft.com) Priority n/a TTL 3600 (1 h)
DKIM A signature on every message · recommended Type CNAME Host name selector2._domainkey Value Copy from Microsoft 365 admin center Looks like: selector2-yourdomain-com._domainkey.<your onmicrosoft prefix>.<letter>-v1.dkim.mail.microsoft (older domains: selector2-yourdomain-com._domainkey.<prefix>.onmicrosoft.com) Priority n/a TTL 3600 (1 h)
DMARC record What to do with fakes · recommended Type TXT Host name _dmarc Value v=DMARC1; p=none; pct=100; rua=mailto:dmarc@yourdomain.com Priority n/a TTL Default
Autodiscover Automatic app setup · recommended Type CNAME Host name autodiscover Value autodiscover.outlook.com Priority n/a TTL 3600 (1 h)

Step by step in IONOS

Verify your domain

Your email provider needs proof that you control this domain before it accepts email for it.

Type
TXT
Host name
Leave this field empty
Value
Copy it from Microsoft 365 admin center (see below)

Where to find your value

In the Microsoft 365 admin center go to Settings > Domains and add your domain (or select it and choose Start setup). On Verify you own your domain, choose Add a TXT record to the domain's DNS records and copy the TXT value.

It looks like: MS=ms followed by digits

  • This record only proves you own the domain. It doesn't affect anything else and can be deleted after verification.
  • Verification usually takes up to 10 minutes after adding the record, sometimes up to 48 hours.

In IONOS

  1. Select Add record, then the TXT section.
  2. Leave Host name empty for your bare domain, paste the Value, and choose a TTL.
  3. Select Save.

Point your MX records

MX records tell every other mail server where to deliver email for your domain. They must point to your provider and nowhere else.

Type
MX
Host name
@
Priority
0
Points to
Copy it from Microsoft 365 admin center (see below)

Where to find your value

In the Microsoft 365 admin center go to Settings > Domains, select your domain, then DNS records > Manage DNS. On the Add DNS records page, expand MX Records and copy the value.

It looks like: <your MX token>.mail.protection.outlook.com, or for domains set up on Microsoft's newer DNSSEC infrastructure <your MX token>.<subdomain>.mx.microsoft

  • Use the highest priority your host allows, typically 0.
  • Remove MX records that point to your previous email provider, or give them a lower priority (a higher number) than the Microsoft 365 record.
  • Add users and mailboxes in Microsoft 365 before switching the MX record so incoming mail keeps flowing.
  • Exchange Online only supports TTL values under 6 hours (21,600 seconds).

In IONOS

  1. Select Add record, then the MX section.
  2. Enter @ as Host name, the mail server in Points to, and the Priority. Choose 1 hour for TTL.
  3. Select Save.
  4. If other MX records are listed, delete each one with the Delete record (trash can) icon.

Add the SPF record

SPF is a TXT record that lists the services allowed to send email from your domain, so receivers can spot forgeries.

Type
TXT
Host name
Leave this field empty
Value
v=spf1 include:spf.protection.outlook.com -all
  • If an SPF record already exists, don't create a second one. Add include:spf.protection.outlook.com to the existing record so there is a single SPF record.
  • Microsoft recommends -all (hard fail) together with DKIM and DMARC.
  • Only one SPF record is allowed per domain, and it must stay under 10 DNS lookups.

In IONOS

  1. Select Add record, then the TXT section.
  2. Leave Host name empty for your bare domain, paste the Value, and choose a TTL.
  3. Select Save.

Set up DKIM (recommended)

DKIM publishes a public key so receivers can confirm your messages really came from you and were not changed on the way.

Type
CNAME
Host name
selector1._domainkey
Alias
Copy it from Microsoft 365 admin center (see below)

Where to find your value

In the Microsoft Defender portal open Email authentication settings (security.microsoft.com/authentication), select the DKIM tab and your domain, then copy the two CNAME values. They are also shown in the admin center under Add DNS records > Advanced options > DomainKeys Identified Mail (DKIM).

It looks like: selector1-yourdomain-com._domainkey.<your onmicrosoft prefix>.<letter>-v1.dkim.mail.microsoft (older domains: selector1-yourdomain-com._domainkey.<prefix>.onmicrosoft.com)

  • Microsoft lists DKIM as optional, but DMARC needs DKIM to align with your domain.
  • After both CNAME records resolve, turn on Sign messages for this domain with DKIM signatures in the Defender portal.
Type
CNAME
Host name
selector2._domainkey
Alias
Copy it from Microsoft 365 admin center (see below)

Where to find your value

Same place as selector1: Defender portal > Email authentication settings > DKIM tab > your domain.

It looks like: selector2-yourdomain-com._domainkey.<your onmicrosoft prefix>.<letter>-v1.dkim.mail.microsoft (older domains: selector2-yourdomain-com._domainkey.<prefix>.onmicrosoft.com)

  • Add both selector records. Microsoft rotates between them.

In IONOS

  1. Select Subdomains, then Add subdomain, and enter the record's name (for example autodiscover).
  2. Under Actions for the new subdomain, select the gear icon, then DNS.
  3. Select Add record, then the CNAME section.
  4. Enter the target in the Alias box, tick the I am aware disclaimer if it appears, and select Save.
  5. Repeat for each CNAME record above.

Add the DMARC record (recommended)

DMARC tells receivers what to do with mail that fails SPF and DKIM, and where to send reports about it.

Type
TXT
Host name
_dmarc
Value
v=DMARC1; p=none; pct=100; rua=mailto:dmarc@yourdomain.com
  • Start with p=none and read the reports, then move to p=quarantine and finally p=reject. pct can step up in stages (10, 25, 50, 75, 100).
  • Replace the report address with a shared mailbox or group, not a personal inbox.
  • Set up SPF and DKIM first.
  • Microsoft 365 doesn't send forensic (ruf) reports.

In IONOS

  1. Select Add record, then the TXT section.
  2. Leave Host name empty for your bare domain, paste the Value, and choose a TTL.
  3. Select Save.

Add the Autodiscover record (recommended)

Autodiscover lets Outlook and other mail apps find your account settings without manual setup.

Type
CNAME
Host name
autodiscover
Alias
autodiscover.outlook.com
  • Optional but highly recommended: lets Outlook and other apps set up mailboxes automatically.

In IONOS

  1. Select Subdomains, then Add subdomain, and enter the record's name (for example autodiscover).
  2. Under Actions for the new subdomain, select the gear icon, then DNS.
  3. Select Add record, then the CNAME section.
  4. Enter the target in the Alias box, tick the I am aware disclaimer if it appears, and select Save.

Check your setup

Once the records are saved, run a live check. We look up your domain in public DNS and tell you what is right, missing or wrong, with the fix in IONOS’s words.

We only read public DNS records. Nothing is stored.

Common mistakes with Microsoft 365 on IONOS

Switching MX before adding mailboxes

Add users and mailboxes in Microsoft 365 before changing the MX record, or incoming mail has nowhere to go.

Adding a second SPF record

Microsoft says not to create a new SPF record if one exists. Add include:spf.protection.outlook.com to the existing record so there is a single SPF record.

Publishing DKIM CNAMEs but not turning on signing

After both selector CNAMEs resolve, switch on Sign messages for this domain with DKIM signatures in the Defender portal.

Using a TTL longer than 6 hours on MX

Exchange Online only supports TTL values under 6 hours (21,600 seconds). One hour (3600) is the recommended value.

IONOS: CNAME records go on their own subdomain

IONOS supports only one top-level CNAME record, so each CNAME is created by first adding a subdomain and then giving it an Alias.

IONOS: MX and a top-level Autodiscover CNAME can't coexist

IONOS doesn't allow a domain to have both an MX record and a top-level Autodiscover CNAME. Microsoft's guide uses the subdomain method above for Autodiscover.

Visit Microsoft 365 Visit IONOS

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Microsoft 365 on IONOS: questions

Where do I add Microsoft 365 DNS records in IONOS?

Sign in at login.ionos.com, select Menu, then Domains and SSL. Under Actions for your domain, select the gear icon, then DNS. Add each record there, one at a time.

What goes in the Host name field at IONOS?

Leave it empty for records on your bare domain, such as MX and SPF. For the others, enter only the part before your domain, for example autodiscover. IONOS adds your domain automatically.

Do I need to delete my existing MX records at IONOS?

Remove MX records that point to your previous email provider, or give them a lower priority (a higher number) than the Microsoft 365 record.

Where do I get my Microsoft 365 DKIM record?

In the Microsoft Defender portal open Email authentication settings (security.microsoft.com/authentication), select the DKIM tab and your domain, then copy the two CNAME values. They are also shown in the admin center under Add DNS records > Advanced options > DomainKeys Identified Mail (DKIM).

Can Microsoft 365 add the records at IONOS for me?

IONOS supports Domain Connect: Microsoft 365 and Zoho Mail can add the records after you sign in to IONOS and select Connect and Allow.

How long until Microsoft 365 email works on IONOS?

DNS changes typically take about 15 minutes to take effect, occasionally longer.

Sources

Every value and step on this page comes from these official pages. Dashboards change, so if something doesn’t match what you see, tell us.

Microsoft 365 on other hosts

Other email providers on IONOS