Cloudron Email Proxy Utility (Email Support for Office 365 via oAuth2.0)

[umnz]

Hi team,

Given Cloudron's already rich email feature set, I've come across a few specific situations where an Email Proxy Utility could be very useful.

Example Use Cases (lifted from the Github)

• You need to use an Office 365 email account, but you don't like the Outlook desktop client. The email client you like doesn't support OAuth 2.0, which became mandatory in January 2023.
• You used to use Gmail via IMAP/POP/SMTP with your raw account credentials (i.e., your real password), but cannot do this now that Google has disabled this method, and don't want to use an App Password (or cannot enable this option).
• You have an account already set up in an email client, and you need to switch it to OAuth 2.0 authentication. You can edit the server details, but the client forces you to delete and re-add the account to enable OAuth 2.0, and you don't want to do this.
• You have made your own script or application that sends or receives email, but it doesn't support OAuth 2.0, and you don't want to have to modify it to implement this.
• You work with multiple services or applications that use IMAP/POP/SMTP, and you don't want to have to set up OAuth 2.0 independently for each one.

Email OAuth2 Proxy (Microsoft 365 / Gmail)
https://github.com/simonrob/email-oauth2-proxy

This tool provides older applications with the ability to send and receive email without having to stay up to date with the latest OAuth2 requirements from Microsoft and Google and is well documented.

Specifically I think this would be useful for tools like OpenProject and Redmine which are not keeping up with modern authentication protocols for things like inbound email monitoring.

But this could also be a way for Cloudron user's to relay via Microsoft and Gmail platforms directly. This could be an interesting opportunity to further expand Cloudron's rich email feature set.

EDIT: Also looks like someone containerised this application - might be a good starting point.
https://www.reddit.com/r/Office365/comments/15s9kb9/oauth_20_proxy_for_email_popimapsmtp_containerized/

[umnz]

Just a bump to see if anyone wants to help me convert this into a custom Cloudron? Microsoft's statement is that SMTP Auth via Basic auth will be retired in September 2025. Which means SMTP via Office 365 will stop working on Cloudron if an alternative solution isn't prepared.

This utility allows you to send and receive using oAuth2.0 which would provide a straight forward solution for Cloudron apps that don't natively support it. Also, it would bypass the requirement to have Port 25 open.