dovecot - Feb 2021 - Sieve regex error "invalid preceding regular expression"

Hi, everyone!

I'm trying to get the detail part of the address (i.e. anything that comes
between + and @ in the address of this type: alias+detail at mydomain.tld) in
this sieve:

if address :regex :localpart "to" "\+(.*)" {
  fileinto :create "${1}";
  stop;
}

However, when I try to compile it with sievec, I get this error:

error: invalid regular expression '+(.*)' for regex match: invalid
preceding regular expression.

Why is that? Shouldn't I escape the plus sign? Itried also not escaping it,
but I get the same error.


(A note why I don't use "envelope :detail" for that purpose:
because the detail part of the address is not preserved in the
"Envelope-To" after the message is redirected from alias to user.
After that redirection the "Envelope-To" contain only user at
mydomain.tld, not user+detail at mydomain.tld.)

-- 
Respectfully,
Denis Shadrin

> On 19/02/2021 07:54 ml at shadrinden.ru wrote:
> 
>  
> Hi, everyone!
> 
> I'm trying to get the detail part of the address (i.e. anything that
comes between + and @ in the address of this type: alias+detail at mydomain.tld)
in this sieve:
> 
> if address :regex :localpart "to" "\+(.*)" {
>   fileinto :create "${1}";
>   stop;
> }
> 
> However, when I try to compile it with sievec, I get this error:
> 
> error: invalid regular expression '+(.*)' for regex match: invalid
preceding regular expression.
> 
> Why is that? Shouldn't I escape the plus sign? Itried also not escaping
it, but I get the same error.
> 
> 
> (A note why I don't use "envelope :detail" for that purpose:
because the detail part of the address is not preserved in the
"Envelope-To" after the message is redirected from alias to user.
After that redirection the "Envelope-To" contain only user at
mydomain.tld, not user+detail at mydomain.tld.)
> 
> -- 
> Respectfully,
> Denis Shadrin
Try '[+](.*)'

Regards,
Aki