[Dovecot] managesieve vacation script bounces/frozen with a 550 error.

[Stephan Bosch]

On 12/26/2011 9:41 PM, Jason X, Maney wrote:
>  I have been trying to get this problem out of the way but I just cant
>  seem to get it right. I hope someone can point me in the right
>  direction here. I have come up with a vacation script as below, which
>  can be send out from my Postfix SMTP server to my smarthost at the
>  ISP, and yet for some reason it is not sent out at my ISP server. The
>  guys at the ISP have sent me the full error they are getting on their
>  Exim SMTP server. My dovecot version is:
[...]
>  550 Bounces must have only a single recipient
[...]
>  What I am not sure of is, is this a problem I need to fix or is it
>  something my ISP need to work on, on their Exim? If its something
>  they can work on can you also give me pointers so I can work with
>  them to fix it?

I googled for this error a bit, and it is probably produced by the 
following custom anti-backscatter Exim acl (various examples float 
around on the internet):

deny senders = :
           condition = ${if ! eq{$recipients_count}{1}{1}}
           message = Bounces must have only a single recipient

This rule only fires when the vacation message triggers multiple RCPT 
commands in the SMTP session with your SMTP. Sieve only replies to a 
single recipient, so apparently somewhere along the mail path additional 
recipients get added and it is likely that this happens at your 
smarthorst. Since this is likely an MTA problem and not a Sieve or 
Dovecot issue, I cannot help you much more.

Regards,

Stephan.