0
votes
0answers
115 views

Spamassassin: using specific DNS server for DNSBL lookups

High volume mailserver. I need 2 things operating simultaneously: local caching nameserver (BIND) rev dns server for DNSBL (SORBS) lookups The way I set it up for now is using RBLDNSD bound to ...
0
votes
0answers
114 views

How to send a test e-mail from an RBL blocked host?

In order to test a whitelisted DNS entry: How can I send an e-mail from a blocked (in RBL) host, is there such a test service even exists?
0
votes
2answers
256 views

Why does mail, from some domain, sent through someisp.com, get blocked by the isp's webserver being listed in RBLs? [closed]

Today I one of our customers forwarded to me a mail from the ISP of one of her mail recipients that says they're blocking my customer's email because our webserver IP is listed in some RBLs. Of ...
1
vote
2answers
125 views

How can I receive mails from otherwise blacklisted servers?

On the mail servers I set up in our company, I use several blacklists in postfix. These really help take care of the spam we get send our way. But every once in a while one of our (potential) ...
6
votes
2answers
227 views

Which DNS Black Lists would you recommend to discard spam in pre-queue?

There are many black lists out there, with bad and good reputations. Also, some people recommend to use RBL lists only in score-based systems (like spamassassin) while others (including commercial ...
1
vote
3answers
60 views

does it still have any sense to directly drop mails that trigger RBLs?

Once upon a time, using RBLs to drop mails was actually a good idea. These days seems it is no more possible for a reason or the other, so every one switched / is_switching to just use RBLs as another ...
3
votes
1answer
4k views

Postfix Whitelist before recipient restrictions

Alright. Some background. We have an anti-spam cluster trucking about 2-3 million emails per day, blocking somewhere in the range of 99% of spam email from our end users. The underlying SMTP server ...
0
votes
4answers
299 views

Does it matter if your web server's IP is RBL'ed?

We have a web server (on Slicehost) with an IP address that has been blacklisted in at least one DNSRBL (FIVETEN). The host is not currently a source of mail, in fact all mail for the domain goes ...
1
vote
3answers
155 views

Are there any tools for comparing DNSBL effectiveness?

I just added a new DNSBL to the list of ones that I use on my small mailserver. I set it up to be first on the list because I wanted to see what it missed but other lists caught. I'm watching mail ...
4
votes
3answers
760 views

Customer's IP Listed on RBL - What steps do you use to prevent black listing?

Customer called saying their e-mail was bouncing from particular vendors. Investigated it and identified they were listed on more than one RBL/CBL. Restricted firewall to only allow traffic on port ...