What do you mean? I use a custom domain in proton so that my server sends emails from info@mydomain instead of my proton email. I have about 10 addresses with three different domains in the essentials plan and I can send emails from different containers as different emails
That’s only for a personal domain that you own and can set the DNS records for. But if you wanted to forward your gmail (or yahoo, or outlook, or whatever other provider that offers a public SMTP server) addresses to your proton mailbox, and be able send emails as those gmail addresses from within your proton mailbox, that’s not supported. See here for what the feature looks like in GMail.
What do you mean? I use a custom domain in proton so that my server sends emails from info@mydomain instead of my proton email. I have about 10 addresses with three different domains in the essentials plan and I can send emails from different containers as different emails
That’s only for a personal domain that you own and can set the DNS records for. But if you wanted to forward your gmail (or yahoo, or outlook, or whatever other provider that offers a public SMTP server) addresses to your proton mailbox, and be able send emails as those gmail addresses from within your proton mailbox, that’s not supported. See here for what the feature looks like in GMail.