Using SMTP Email Address in Outlook?

Question

Using SMTP Email Address in Outlook?

Jake Woods 25

I've been able to successfully add a SMTP username in Azure by setting up an Entra application, domain etc. I have the username added.

Now I don't understand how to login to this account with Outlook. I've never set a password for this SMTP username so I feel like I'm missing some steps.

The end goal is to have an email address for my custom domain like myname @ mycustomdomain.com and add it to Outlook so I can send/receive email from it.

Any advice is appreciated.

Bhargavi Naragani 7,445 Reputation points Microsoft External Staff Moderator

2025-08-08T15:43:28.1333333+00:00

Hi Jake Woods,

Can you confirm if you’re using Azure Communication Services (ACS) Email to send emails via SMTP, or are you trying to use a Microsoft 365/Exchange Online mailbox?"

Which ACS Email SDK are you planning to use for your SMTP setup? (For example, .NET, JavaScript, Python, Java- as per this SDK feature list?)

Are you planning to only send emails from this address via SMTP, or do you also need to receive emails in Outlook?

How did you create your SMTP username, did you also generate the corresponding access key/password from the ACS resource?

Do you specifically want to configure this SMTP account directly in Outlook, or is Outlook only for monitoring the mailbox from Exchange Online?

Help us with requested information to check and assist you further on this.
Jake Woods 25 Reputation points

2025-08-08T15:50:24.97+00:00

Thank you, those questions alone are helpful because they're not ones I know to ask. I'm using ACS but I want an inbox too so should I be using something else?

I was hoping to use PHP but since it doesn't appear to be listed, probably Javascript or Python.

I need to send and receive emails so maybe suggestions on how to set this up would be great.

I'm used to using Plesk for single machine web apps so that was easy, just click email and add a username/password combo, but this seems to be more complicated and I'm trying to learn it.

2 answers

Your answer

Bhargavi Naragani 7,445 Reputation points Microsoft External Staff Moderator

2025-08-08T15:43:28.1333333+00:00

Hi Jake Woods,

Can you confirm if you’re using Azure Communication Services (ACS) Email to send emails via SMTP, or are you trying to use a Microsoft 365/Exchange Online mailbox?"

Which ACS Email SDK are you planning to use for your SMTP setup? (For example, .NET, JavaScript, Python, Java- as per this SDK feature list?)

Are you planning to only send emails from this address via SMTP, or do you also need to receive emails in Outlook?

How did you create your SMTP username, did you also generate the corresponding access key/password from the ACS resource?

Do you specifically want to configure this SMTP account directly in Outlook, or is Outlook only for monitoring the mailbox from Exchange Online?

Help us with requested information to check and assist you further on this.
Jake Woods 25 Reputation points

2025-08-08T15:50:24.97+00:00

Thank you, those questions alone are helpful because they're not ones I know to ask. I'm using ACS but I want an inbox too so should I be using something else?

I was hoping to use PHP but since it doesn't appear to be listed, probably Javascript or Python.

I need to send and receive emails so maybe suggestions on how to set this up would be great.

I'm used to using Plesk for single machine web apps so that was easy, just click email and add a username/password combo, but this seems to be more complicated and I'm trying to learn it.

Answer 1

Hi Jake Woods,

You can’t use just an SMTP username to log into Outlook. You must create a licensed Microsoft 365 user with a mailbox to send and receive emails in Outlook with your custom domain.

To send/receive email using ******@mycustomdomain.com in Outlook:

Ensure your custom domain is added and verified in Microsoft 365

Go to Microsoft 365 Admin Center → Settings > Domains
Add mycustomdomain.com and follow the DNS steps to verify it.

Create a user mailbox

Go to Microsoft 365 Admin Center → Users > Active users
Create a new user with the email ******@mycustomdomain.com
Assign them a Microsoft 365 license that includes Exchange Online (like Microsoft 365 Business Basic, Standard, or an Exchange Online Plan).
This gives : A mailbox, Sign-in access and Outlook access

Set a password for the user

You’ll be prompted to set one when creating the user. You can always reset it later.

Sign in via Outlook

Open Outlook and log in with:
Email: ******@mycustomdomain.com
Password: the one you set in the Microsoft 365 portal

DNS Records for Email (MX, SPF, etc.)

Make sure you've correctly configured DNS for your domain:

MX record pointing to yourdomain-com.mail.protection.outlook.com
SPF record like v=spf1 include:spf.protection.outlook.com -all

These ensure your email can be sent/received correctly.

add-a-custom-domain-name

connect-your-domain-to-office

recipients-in-exchange-online/create-user-mailboxes

Siva Nair 345 Reputation points Microsoft External Staff Moderator

2025-08-11T16:55:04.0733333+00:00

Hi Jake Woods,

Thanks for mentioning it as answer, As you cannot accept your own answer, i would request you to please accept it , so that it will be helpful for others with similar queries.

Thanks!

Best wishes

Answer 2

Answered by Siva Nair but can't mark a comment as an answer.

Hi Jake Woods,

You can’t use just an SMTP username to log into Outlook. You must create a licensed Microsoft 365 user with a mailbox to send and receive emails in Outlook with your custom domain.

To send/receive email using ******@mycustomdomain.com in Outlook:

Ensure your custom domain is added and verified in Microsoft 365

Go to Microsoft 365 Admin Center → Settings > Domains
Add mycustomdomain.com and follow the DNS steps to verify it.

Create a user mailbox

Go to Microsoft 365 Admin Center → Users > Active users
Create a new user with the email ******@mycustomdomain.com
Assign them a Microsoft 365 license that includes Exchange Online (like Microsoft 365 Business Basic, Standard, or an Exchange Online Plan).
This gives : A mailbox, Sign-in access and Outlook access

Set a password for the user

You’ll be prompted to set one when creating the user. You can always reset it later.

Sign in via Outlook

Open Outlook and log in with:
Email: ******@mycustomdomain.com
Password: the one you set in the Microsoft 365 portal

DNS Records for Email (MX, SPF, etc.)

Make sure you've correctly configured DNS for your domain:

MX record pointing to yourdomain-com.mail.protection.outlook.com
SPF record like v=spf1 include:spf.protection.outlook.com -all

These ensure your email can be sent/received correctly.

add-a-custom-domain-name

connect-your-domain-to-office

recipients-in-exchange-online/create-user-mailboxesHi Jake Woods,

You can’t use just an SMTP username to log into Outlook. You must create a licensed Microsoft 365 user with a mailbox to send and receive emails in Outlook with your custom domain.

To send/receive email using ******@mycustomdomain.com in Outlook:

Ensure your custom domain is added and verified in Microsoft 365

Go to Microsoft 365 Admin Center → Settings > Domains
Add mycustomdomain.com and follow the DNS steps to verify it.

Create a user mailbox

Go to Microsoft 365 Admin Center → Users > Active users
Create a new user with the email ******@mycustomdomain.com
Assign them a Microsoft 365 license that includes Exchange Online (like Microsoft 365 Business Basic, Standard, or an Exchange Online Plan).
This gives : A mailbox, Sign-in access and Outlook access

Set a password for the user

You’ll be prompted to set one when creating the user. You can always reset it later.

Sign in via Outlook

Open Outlook and log in with:
Email: ******@mycustomdomain.com
Password: the one you set in the Microsoft 365 portal

DNS Records for Email (MX, SPF, etc.)

Make sure you've correctly configured DNS for your domain:

MX record pointing to yourdomain-com.mail.protection.outlook.com
SPF record like v=spf1 include:spf.protection.outlook.com -all

These ensure your email can be sent/received correctly.

add-a-custom-domain-name

connect-your-domain-to-office

recipients-in-exchange-online/create-user-mailboxes

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Using SMTP Email Address in Outlook?

2 answers

Your answer