You are now able to set up Custom SMTP right from your platform!
What Is a Custom SMTP?
In simple terms, custom SMTP is a feature that allows you to set up a customized email address that the platform will send mail from. This is yet another step in white-labeling your platform.
Important Update – Microsoft SMTP Authentication
As of September 2025, Microsoft will retire Basic Authentication (username/password) for SMTP in Exchange Online. To ensure uninterrupted service, eloomi now supports OAuth 2.0 authentication for Microsoft 365.
The existing Microsoft 365 connector has been renamed to Microsoft 365 – Legacy
A new, secure option named Microsoft 365 – OAuth has been introduced
Learn more from Microsoft's official documentation
We strongly recommend switching to OAuth before the deprecation deadline of September 2025.
How to Set Up Custom SMTP
Upon navigating to Admin > Integrations, you will see the option for Custom SMTP:
2. Clicking Configure will bring up this page:
3. Select any of our available providers then click Next. To demonstrate this functionality, we will select Microsoft 365:
4. From here, you will see that the host and port are pre-filled, meaning there is no action needed for these fields. You will, however, need to ensure that you are providing the correct username and password of your provider:
If you are using Microsoft 365 Legacy, you will need to enter your Microsoft account username and password.
⚠️ Note: 2FA must be disabled, or you must use an App Password.
Microsoft will deprecate this method by September 2025, so we recommend switching to the OAuth option.
If using Microsoft 365 OAuth, you will be redirected to Microsoft to authenticate and grant access to eloomi. Password entry is not required in this step.
NOTE: Please make sure 2FA is disabled for the user you are using to connect with.
5. Once you provide the necessary information, you can then create a sender name and sender address. This is what will be displayed to your people when they receive emails from your platform:
6. Once all the fields are correctly filled in, click Next. You will then be brought to the testing page, where you can test the connection by sending a test email to any email address you choose. This is where the system will ensure that the information provided is correct to avoid anything being set incorrectly. If you're using OAuth, ensure the Microsoft login process completes successfully before proceeding with the test email:
7. If there is an error, the Confirm button will be greyed out and you will be directed back to the initial setup page to fix the errors:
8. However, if every previous step was completed fully and correctly and the connection test was successful, the system will send a test email to the email address provided. Double-check to ensure that you have received the email and everything in the test email looks right. Once you have checked and everything looks good, click Confirm to finalize the setup:
9. Upon confirming and completing the setup, you will be brought back to the custom SMTP overview. From here, you can test the connection again, and enable or disable the integration as well:
10. On this page, you will also see two more options upon completing setup:
Settings - This will bring you back to the initial setup wizard should you wish to make any changes to the integration.
Bin icon - This will delete the integration.
Troubleshooting
If you're using Microsoft 365 – OAuth and the test fails, ensure your Microsoft tenant admin has granted consent to the eloomi SMTP integration in Azure.
If you're still using the Legacy option and encounter errors, it's possible that Microsoft has already blocked Basic Auth for your organization.
If you have any other questions or concerns, please feel free to reach out to our support team via Intercom chat or email us at support@eloomi.com.