Yes they support it.
https://proton.me/support/email-forwarding

neither proton, nor tuta :\

Automatically forwarding emails. You can let incoming emails be automatically forwarded to another address.
How to automatically forward emails:
Enable the Auto forward button .
Enter the email address to which you want to forward the messages.
In order to keep a copy of the email, enable Keep a copy of the message.
The auto forwarding will be entered as email filter. If additional filter rules are to be applied after the auto forwarding, enable Process subsequent rules.

mailbox.org 👍

Filtering Emails by Using Rules
Email filters help you organize incoming email messages. An email filter consists of one or several rules. By setting rules you can e.g. trigger the following actions:

The email is moved to a specific email folder.
The email is forwarded to another email address.

👍👍

Been using Zoho mail with my domain for years.

https://www.zoho.com/mail/help/email-forwarding.html