On macOS 13.1 (Ventura) I have an Apple Mail rule that is setup to Forward a received email to a specific email address. In addition to forward, it will set the color of the message.
I have tested the rule, and the message color is set, confirming the rule is firing, but it will not forward the email. I have tried to use Forward, Forward with Message, and Redirect. None of these options will result in the email being sent to the designated address. I also tried different addresses, but still no luck.
I am using Proton Mail in this case, but I tried using Gmail instead and it works fine. So, it appears to be related to the use of Proton Mail, but I can't be certain.
Has anyone been able to get an email forwarding rule to work in Apple Mail and if so, anyone done so with Proton Mail?
For those who aren't familiar with Proton Mail, they don't support email forwarding on their server and they require the use of a IMAP proxy app they call Proton Bridge, which encrypts and decrypts messages from an IMAP email client to the Proton Mail service.