[Dovecot] recipient delimiter results in sieve errors

[Gregory Mokhin]

> Well, I'm confused. Did you want mok+test@ to deliver to "mok" user and
> "test" mailbox? If not, what did you want the "+" delimiter to do then?
>

I wanted to use amavis feature to auto-add +spam, +badh etc. to the
addresses, including those relayed to non-local recipients. The message to
mok+test is to be delivered to "mok" user. These extensions can be used,
for example, for client filtering.

My Sieve script filters spam based on the presence of X-Spam-Flag header:

if  header :matches ["X-Spam-Flag"] [
    "YES"
]
{
fileinto "INBOX.Spam";
}

It fails with the presence of +test, +spam or any other extension with
that generic error.

Regards,
Gregory