I wanted to build a prefilter for a mailbox in order to convert this mailbox into a simple mailing list. Only a very small circle of senders should be able to send to the distribution list (in the following example this is email@example.com). If it should be another sender, he should get a corresponding notification and preferably his original mail forwarded in the attachment.
I have created the following Sieve Code for this purpose:
if anyof (
header :contains “From” “firstname.lastname@example.org”
vacation :days 99 :addresses [“email@example.com”] :subject “Not allowed”
“Its not allowed for you to send to that Mailinglist”;
Unfortunately this is not validated:
Sieve Parser: line 13: unknown command attach
Is there a workaround for that to do? Or is it not possible to do that with this sieve Version which is in the mailcow dockerized Version?
I would be very happy about help