Sieve is perfectly capable of forwarding email. This would be a great added feature!

I need this for a workaround to get functionality that is missing from Proton Mail. Forwarding specific emails will allow me to process these emails elsewhere while still getting all mail delivered to Proton first.

Need a way to forward emails received by a SimpleLogin alias. Either abide by the forwarding rule set up for the underlying email address (right now it's ignored if the email is received via alias), or provide the sieve redirect capability to forward the email.

Same here. Need to forward e-mail that is still coming to my personal inbox after migrating to proton. This worked on my old email server, also with sieve.

I need this to be able to reroute work-related email to my work inbox.

Essential for building a good mail workflow

This sieve feature is essential for email workflow.
I like to forward purchase invoices to our accounting system automatically.

This is essential for shared accounts that require email verification codes.

+1 def need a redirect

Also opened a github issue on it if you like to comment / up it there:

https://github.com/ProtonMail/libsieve-php/issues/38

I also need the Sieve redirect to be able to organize and delegate incoming e-mails ... plz prioritize this!

Without this, I can't delegate emails to my assistant.

I just want to redirect newsletters to another service. Please add this :)

Conditional forwarding would be very important. Even being able to generate and email based on a filter being satisfied would do as well.
Thanks

+1
Target Use Case: I'd like to forward informed delivery digests (physical mail summaries) to an external system for automated processing and notification. The post office does not allow me to specify a different email just for informed delivery notices.

+1 for `redirect`

Really miss this feature :-(

In our family situation I would like this feature to be able to create additional addresses (for our own domain name) for our kids and forward it to both parents. Adding a separate account for this would (a) be cosly and (b) would need us to check multiple inboxes. Forwarding would be much more user friendly and would help us a lot!

i think it is overlooked feature. Current sieve implementation allows mail rejections. I'd argue - redirect(forward) copy shouldn't be missing. all sive script are executed before inbox delivery. and considering that headers are not encrypted it should be straightforward.