Hello Proton Team,

I would like to suggest an improvement regarding the integration between Proton Mail, Proton Pass, and SimpleLogin.

Currently, if a custom domain is configured in Proton Mail, it cannot also be used for aliases in SimpleLogin. This creates an unnecessary limitation within what is presented as a unified Proton ecosystem.

As a customer using multiple Proton services, I expected my verified custom domain to be available across all Proton products without requiring separate configurations or forcing me to choose between receiving email through Proton Mail or creating aliases through SimpleLogin.

Suggested Improvement

Once a domain has been verified in a Proton account, users should be able to:

• Use the same custom domain for Proton Mail addresses.
• Create SimpleLogin aliases under that same domain.
• Generate Hide-my-email aliases in Proton Pass using the same domain.
• Manage everything from a single interface, without duplicate DNS configuration or ownership verification.

Why This Matters

The current separation creates unnecessary friction:

• Users must choose which Proton service "owns" the domain.
• It breaks the feeling of a unified ecosystem.
• It makes custom-domain alias management more complicated than it needs to be.
• It discourages users from fully adopting Proton Pass and SimpleLogin together.

Possible Implementation

One approach could be introducing a "Shared Domain" model.

A verified domain would belong to the user's Proton account rather than to an individual product. Each address or alias could then simply be assigned to Proton Mail or SimpleLogin while sharing the same DNS configuration and encryption infrastructure.

This would provide a much more seamless experience while preserving security and maintaining clear separation between mailboxes and aliases.

Thank you for considering this suggestion. I believe this would significantly improve the experience for users who rely on custom domains and use multiple Proton services as part of the Proton ecosystem.