Enable Forwarding
I have a paid Proton account and two unpaid Proton accounts. I have two unpaid Proton accounts, because aliases are not feasible. Choosing the wrong outgoing alias annuls all my privacy efforts immediately.
I would thus like to forward mails from my unpaid accounts to my paid one, to have one central account for reading mails and receiving notifications for incoming ones. To my surprise, I found out that basic forwarding is a paid feature. That's very greedy. Even more so, given that I want to forward to a paying customer (me).
I want to note that Proton Mail makes it ever so obvious that you can forward from Google and other services to Proton Mail. It's a marketing point on the free tier. It even deserves its own settings-tab, which is coincidentally neatly separated from the settings-tab that concerns forwarding from Proton Mail.
I found this reddit post with the same issue
https://www.reddit.com/r/ProtonMail/comments/1581n9l/please_make_imap_smtp_pop_or_mail_forwarding_free/
As he said, even "evil Google" allows forwarding and you make it a big marketing point that they do. It allows you to have a user switch seamlessly to Proton. The audacity.