A: Hi,

It's Alex, the founder of ProxiedMail.
Thank you for your question.

There are 2 ways to add one more real email:
1. In case you want just to add it to the system:
Start creating the new proxy email as usual and specify desired real email in "Enter your real email" input. Then, please create proxy email with that real email.
You might need to verify it and then it would appear as the last one used by you (filled by default in real email dropdown).
So, this way, every time you're creating the proxy email, you would be able to choose from dropdown.
2. If you need to make emails to be forwarding to both real emails you need to:
Choose proxy email where you want to add real address, click "more" that would expand more features, click "Add new real address". Then, desired proxy email address would appear with the input. For this case, just enter additional real address in the input and click "Create".
After verification, all emails tied up to proxy email would be forwarded to both real addresses.

Regarding the documentation and tutorials we have:
https://docs.proxiedmail.com/docs/intro/ - API & bots documentation
https://medium.com/@yatsenkolesh - medium & promo materials (there is something useful too)
https://www.youtube.com/channel/UCP3co_J1bjKrontA1KqUcnQ/ - a bit of tutorials regarding the custom domains on YouTube
https://proxiedmail.com/en/faq - advanced FAQ.

Let me know if you have any additional questions.