Bummer, not really.
Our mail-flow situation in general is on the stranger side. We have a proton mail address acting as our support box, and sending mail out with ITFlow.
However, the IMAP integration does not work. So, proton forwards mail to an intake gmail account, which has the IMAP monitored by ITFlow.
So, the ticket is coming in from a forward on the proton address to the gmail address using IMAP, and the responses are coming from the support box via SMTP.
We still want the ticket to come in and the gmail doesn't do any sending. So, nothing we can do there.
Proton doesn't seem to have any ability to add "BEFORE SEND" rules.
I was hoping I could add the alerts email as a client/contact, and set that client/contact to not receive notifications but it doesn't look like there's no native support for that in ITFlow.