BACKSCATTERER temporally blacklisted even if my server return error 550 on unknown recipient
Charly
My SMTP server is blacklisted on backscatterer.org, that means I
accept unknown recipient. But it is not the case. My server return
"550 5.1.1 <us...@mail.com>: Recipient address rejected: User unknown
in virtual mailbox table".
I declared reverse DNS and SPF. My server is not an open relay. It
uses greylists, blacklists, sender and recipient restrictions ... What
could be the problem ?
Thank's in advance
Regards
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Shmuel (Seymour J.) Metz
10/28/2009
at 09:39 PM, Charly <charly...@gmail.com> said:
>My SMTP server is blacklisted on backscatterer.org, that means I accept
>unknown recipient.
No, it means that you send a DSN, which could be, e.g., out of space.
Unknown recipient is just one of several problems, albeit the most common
and the easiest to deal with.
>But it is not the case. My server return
>"550 5.1.1 <us...@mail.com>: Recipient address rejected: User unknown in
>virtual mailbox table".
Do you mean that your respond to, e.g., RCPT, with that text, or that you
send that text in an e-mail?
>What could be the problem ?
Have you searched your logs? Do you have a cached list of valid mailboxes
that could get out of synch? If you use an external server, e.g., LDAP, to
validate mailboxes, what happens if the link to that server is congested
or down? Do you have a secondary MX that could be out of synch?
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Rob
> Hi,
>
> My SMTP server is blacklisted on backscatterer.org, that means I
> accept unknown recipient. But it is not the case. My server return
Your assumption is incorrect. Please visit backscatterer.org to read
the real story.
Charly
<spamt...@library.lspace.org.invalid> wrote:
> In <4956fba4-8463-4876-a841-4f551e895...@g23g2000yqh.googlegroups.com>, on
> 10/28/2009
> at 09:39 PM, Charly <charly.gu...@gmail.com> said:
>
> >My SMTP server is blacklisted on backscatterer.org, that means I accept
> >unknown recipient.
>
> No, it means that you send a DSN, which could be, e.g., out of space.
> Unknown recipient is just one of several problems, albeit the most common
> and the easiest to deal with.
>
> >But it is not the case. My server return
> >virtual mailbox table".
>
> Do you mean that your respond to, e.g., RCPT, with that text, or that you
> send that text in an e-mail?
>
emulating smtp session by telnet.
> >What could be the problem ?
>
> Have you searched your logs? Do you have a cached list of valid mailboxes
> that could get out of synch? If you use an external server, e.g., LDAP, to
> validate mailboxes, what happens if the link to that server is congested
> or down? Do you have a secondary MX that could be out of synch?
>
According to history, the logs expired. I use SQL database as external
server. There is no cache list. If SQL server fails, a timeout occurs
after the RCTP.
My secondary MX also points to the same mail server.
Today, my primary MX is no more listed due to expiration. I figure out
that BACKSCATTERER is going to check again my server during next
days. I will check the log.
> --
> Shmuel (Seymour J.) Metz, truly insane Spews puppet
> <http://patriot.net/~shmuel>
>
> I reserve the right to publicly post or ridicule any abusive
> E-mail. Reply to domain Patriot dot net user shmuel+news to contact
> me. Do not reply to spamt...@library.lspace.org
Shmuel (Seymour J.) Metz
11/03/2009
at 12:07 AM, Charly <charly...@gmail.com> said:
>It's the DSN returned by text during SMTP session.
Let's try this again. A DSN is, by definition, sent *after* the SMTP
session and, if sent to a forged address, is backscatter. If you really
mean DSN then you need to change your SMTP configuration to not respond
250 when the message is not deliverable.
>I figure out that BACKSCATTERER is going to check again my server
>during next days.
AFAIK, UCEPROTECT does not test mail clients for backscatter, it simply
notes the arrival of backscatter at spam trap addresses.
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<http://patriot.net/~shmuel>
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E-mail. Reply to domain Patriot dot net user shmuel+news to contact
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