Add Support for SimpleLogin-Compatible API for Automated Alias Creation

[geilername]

Summary

This feature request proposes integrating a SimpleLogin-compatible API (or something simillar) into Mailcow to allow automated creation of email aliases via integrations with tools like Bitwarden or Vaultwarden (if we decide for a custom Mailcow API I'd also implement the client Side in Bitwarden/Vaultwarden e.g. Bitwarden Client for SimpleLogin). The API would build on Mailcow's existing temporary alias functionality, extending it to support long-term durations (e.g., up to 100 years). Additionally, the authentication system would be expanded to allow each user to have their own API key for this service, and the ability to send as these aliases would also be included.

Motivation

• Many users rely on tools like Bitwarden or Vaultwarden to manage email aliases for privacy and security. Currently, creating aliases in Mailcow is a manual process.
• A similar feature was requested in #4602, which suggests support for AnonAddy. As SimpleLogin is a comparable service, this proposal builds on that idea.
• Per #5041, each user should be able to have their own API key to access this service securely.
• As mentioned in #5759, users should also be able to send emails as the aliases they create.
• This request ties in with #3892, which suggests extending the random alias functionality to allow for permanent durations.

Additional context

Proposed Features:

1. API Integration
   Introduce an API compatible with SimpleLogin, allowing third-party tools like Bitwarden or Vaultwarden to create aliases programmatically.

2. Temporary Alias Enhancements
   Leverage the existing temporary alias system in Mailcow but add the option for long-term alias durations (e.g., up to 100 years).

3. Authentication Update
   Extend the current API token system to ensure each user can have their own API key for secure access.

4. Send-As Alias Support
   Ensure that users can send emails using the aliases they create through this API.

Benefits:

• Simplifies the process of managing email aliases for end users.
• Improves interoperability with widely used tools like Bitwarden and Vaultwarden.
• Provides a privacy-conscious and seamless email aliasing experience.

Offer to Implement:

I’m offering to implement this feature together with a friend of mine and contribute it to the project if there’s interest and agreement from the maintainers.

Looking forward to hearing your feedback!

[DerLinkman]

Hello,

we already thought of this idea too and liked it in general. However we delayed it back to do it on our own.

If you and your friend wan't to contribute this, we'll don't decline that :)

@FreddleSpl0it what do you think?