How to allow users from other organisations to sign up and send e-mails using their own Microsoft365 or Outlook e-mail accounts?

Tom Murmylo 0

Hi there, I'm building an online invoicing app. I want users to be able to provide their e-mail credentials, so the invoice will be sent to their customer from their e-mail directly. These users are clients, they have no connection to me. I am currently using SMTP and app passwords, but this is tricky and not everyone accepts the risks. I have built the connection and am able to use my own accounts, but when someone else tries to log in, they get an error: Selected user account does not exist in tenant XXXXX and cannote access the application .... The account needs to be added as an external user in the tenant first. Please use a different account. Now I understand that e.g. iPhone / Android mail clients don't have that problem, I can log in through Microsoft and use my e-mails there. I'm looking for such a solution. Thank you

Miguel Gonçalves | AVANADE 886 Reputation points

2024-06-11T22:51:54.0333333+00:00
Hi Tom, Some notes:

Instead of using SMTP and app passwords, you can consider implementing OAuth authentication for email services. OAuth allows users to grant your app permission to access their email accounts without sharing their actual credentials (passwords).

Alternatively you can integrate directly with email provider. Some email clients (like iPhone and Android mail apps) have built-in integrations with popular email providers. You can leverage these integrations by allowing users to log in through their Microsoft or other email accounts directly within your app.

You have also INVOICE solutions in the market that allows you to completely whitelabel your billing emails by sending them through your own email domain using SMTP credentials

Share via

How to allow users from other organisations to sign up and send e-mails using their own Microsoft365 or Outlook e-mail accounts?