When an email is sent via a reverse alias, forwarding that same message (e.g., to add a missed recipient) reveals the sender’s real Proton Mail address instead of the alias. Users must manually edit the forwarded message to hide their real address, which is easy to forget and defeats the privacy purpose of reverse aliases.

Steps to Reproduce:

1. Create a reverse alias (e.g., alias@protonmail.com).
2. Compose and send an email to Recipient A using that alias.
3. Realize you omitted Recipient B and click Forward on the sent message.
4. In the compose window, add Recipient B and send.
5. The forwarded email’s From/Reply‑To header now shows your primary Proton Mail address, not the alias.

Expected Behavior:

When forwarding a message that you originally sent using a reverse alias, the forwarded email should automatically retain the alias in the From/Reply‑To fields, keeping your real address hidden without any extra effort.
Suggested Solution:

• Automatic Alias Retention for Forwarded Sent Mail
• Detect that the message being forwarded originated from a reverse alias.

• When the user forwards that message, pre‑populate the From and Reply‑To fields with the original alias.
  Show a non‑intrusive indicator (e.g., “Forwarding using reverse alias”) so the user knows the alias is being used.
  Optional User Preference (under Settings → Aliases → Forwarding)
  “Preserve reverse alias when forwarding my own sent messages” (ON by default).

• Allow advanced users to disable the behavior if they intentionally want the real address shown.

Thank you in advance