Questions tagged [blacklist]

A blacklist is a basic access control mechanism that rejects elements included in the list.

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4 answers
6k views

squid blacklist solution

I've installed squid proxy server for a company and now they ask me to add blacklisting capabilities for squid. The most obvious thing that comes to mind is just to find a huge blacklist file on the ...
3 votes
3 answers
3k views

How to unblacklist an email at Microsoft/OutLook/hotmail

When trying to send email to clients who use Hotmail/Outlook/etc type email addresses, I get the following error: SMTP error from remote mail server after RCPT TO:[email protected]: 550 5.4.1 Recipient ...
0 votes
0 answers
57 views

SSL certificates and firewall blacklists

We have a domain, erbaharlab.com, which we have bought for our research group. www.erbaharlab.com contains our research group website, nanospacejm2.erbaharlab.com contains a conference website and ...
0 votes
1 answer
215 views

fail2ban include list of ip addresses to ban

Suppose I have a .txt file containing a list of ip addresses I'd like to ban for some amount of time (so, a blacklist file of some sort). I know how do do this in Apache (for example) - simply by ...
26 votes
5 answers
108k views

Whitelist allowed IPs (in/out) using iptables

I have a few ip ranges to which I want my server to able to connect and users to connect from. Everything else should be blocked. How should I do that with iptables? My OS is Debian based linux ...
2 votes
2 answers
1k views

fail2ban txt list creation of banned IP

using fail2ban for years, working nice, would like to automate and harden the security for my router. So I would like that fail2ban created a local file, example, list.txt file with a list of banned ...
0 votes
1 answer
55 views

Nginx - Black list cookies

Is there a way to black list cookies purely through Nginx? I tried this: https://stackoverflow.com/questions/67548886/remove-specific-cookie-in-nginx-reverse-proxy But it doesn't seem to cover cases ...
-1 votes
8 answers
40k views

Remove blacklist from spamRATS

I have checked my IP in SpamRATS and the result is the following: Standards Compliance: Does IP Address resolve to a reverse hostname... Passed! Does IP Address comply with reverse hostname ...
2 votes
1 answer
2k views

How should I manually add IP addresses to denyhosts?

I have a few IP addresses I want to add manually to denyhosts because they're huge sources of inbound spam. What's the best way to do this? Or should I not be messing with it? I want to manually ...
0 votes
1 answer
2k views

fortimail antispam has blacklisted the internal exchange mail server address

i have an exchange server for which i wanted to redirect outbound messages throught a fortimail antispam box. i created a new send connector for a test domain and used the ip of the antispam as the ...
0 votes
0 answers
483 views

Sendgrid IP Address Consistently Blocked on RATS-Spam

Overview For our application, we use SendGrid to send emails to many of our users. Recently over the past few weeks, our SendGrid IP addresses have been added to the RATS-Spam blacklist multiple times....
2 votes
2 answers
811 views

Symantec adds email server IP address to blacklist without any proof - how to fight them?

Recently noticed that email server IP address 88.119.185.129 is added to Symantec email blacklist. This IP is clean, not listed at any blacklists. The email server is not open relay, all emails are ...
0 votes
1 answer
1k views

IIS IP Address and Domain Restrictions or Dynamic IP Address Restrictions?

I would like to implement dynamic ip address based restrictions in my IIS 10 on Windows Server 2019, and find a way (even it involves some programming/scripting/automation) to integrate it with ...
0 votes
0 answers
1k views

Reverse DNS Not Working on some Email servers

We host our email on an internal server. Recently we have started getting bouce backs from various other servers. Most seem to have the following error: Reason: Remote SMTP Server Returned: 550 ...
0 votes
0 answers
230 views

Getting email spam blacklist lists

Hi for protecting my organisation i want to get a full list of email spam blacklists from various lists. mxtoolbox for instance is able to check an ip against many many blacklists, however is it free ...
1 vote
1 answer
293 views

How to minimize chances of one's domain being falsely blacklisted (uribl)

My side job is to admin my wife's company domain. It's only used as a domain name for Google mail and tools (slides, docs, etc...). Although she used her domain for email for many years without any ...
21 votes
4 answers
3k views

What are the best methods for catching snowshoe spam?

I'm using Smartermail for my small mailserver. We've been having a problem lately of getting waves of snowshoe spam that follow the same pattern. They come in batches of 3 or 4 at a time. The ...
1 vote
0 answers
255 views

Location of authpriv.notice logs on Bitnami

I have a Bitnami server, Ubuntu Xenial, on AWS LightSail. I followed this tutorial to restrict SSH connections by country. This script ipfilter.sh filters IP addresses: #!/bin/bash # License: WTFPL # ...
0 votes
3 answers
535 views

How to delist DNSBL?

Can not send email to some email addresses that it looks like they are using Office 365. The NDR message is coming from DnsConnectorDelivery which is: [{LRT=11/6/2020 12:11:09 PM};{LED=451 4.4.0 ...
0 votes
0 answers
193 views

How to check if my server's IP has somehow been blocked by some ISP?

I have an app, published on Play Store and App Store, that works via API with our webservices. Nothing fancy, really really basic stuff. Now, some customers can't use the app because it can't reach ...
0 votes
1 answer
80 views

Cyren (Zxyel) classified my fresh website as a "Spam Site". I have never hosted a mail server. What now?

About a month ago I bought a cheap VPS from a popular provider, and also bought a new domain name for it. It hosts Nextcloud and TT-RSS, and I have never sent an email from it -- yet on http://...
0 votes
1 answer
437 views

Apache 2.2 IP address blacklist

I wanted to blacklist on the fly some IP address. I'm updating the main httpd.conf but i wanted to add some IPs on the fly, without using .htaccess (neither the heavy fail2ban). So, i creating a list ...
3 votes
3 answers
11k views

Black Hole DNS on Windows DNS Server

I am looking at configuring our Windows DNS Servers for some type of DNS based blackhole operation. Ideally, we would be able to use feeds from MalwareDomains.com or the like. I was curious how one ...
7 votes
5 answers
36k views

How do I get my server off the ivmSIP/24 blacklist?

I checked my server IP using this tool: http://www.mxtoolbox.com/SuperTool.aspx It's come up on the ivmSIP/24 list. What can I do to get my IP removed from this list? I have SPF records set to allow ...
0 votes
1 answer
47 views

Finding emails filtered by a blacklist

my postfix is configured to forward emails from a domain to an icloud.com email. Unfortunately, my server landed in one of the blacklists that icloud is using and now my client is not receiving his ...
6 votes
2 answers
4k views

How to blacklist or whitelist lots or few ip ranges with ipset and iptables + fail2ban

EDIT: It's astonishing how the urge to find a solution sometimes is sufficient to slowly but steadily lead one towards a solution. Also, the more often I reread my question in order to clarify it, I ...
6 votes
2 answers
2k views

Spamassassin: Bypass /etc/resolv.conf DNS for querying DNSBL?

Question Is there a way to let spamassassin bypass my linux system's dns servers to query DNSBLs? Background Info When my Server receives email, it is checked by spamassassin. One of this checks ...
4 votes
1 answer
4k views

How do I tell Amazon SES their IP addresses are blacklisted?

Is there an official way to tell Amazon SES about blacklisting, and ask them to talk to the other company involved? I have had emails disappear this week and last week (Ironport doesn't even send ...
0 votes
1 answer
5k views

Google blacklist removal

One of the email accounts on my Debian server has been compromised (too weak password set by a client) and it was sending countless spam messages over three days. Once I've found out that out (, I'...
2 votes
1 answer
3k views

Why the ip can't be banned with postfix blacklist?

vim /etc/postfix/main.cf smtpd_recipient_restrictions = check_sender_access hash:/etc/postfix/access Add some ips in /etc/postfix/access vim /etc/postfix/access 86.111.171.141 REJECT 191.96.249....
0 votes
2 answers
922 views

How to block access to web-hosting servers?

Is there a way to block all web-hosting servers trying to access my server? There are a lot of hacked websites used to do damage to my server and only common thing is IP of agressor (many of IP's) is ...
0 votes
2 answers
2k views

Active Directory password change: Re-Allow current password?

My question is that simple: Can I configure an active directory in a way that when a user wants/needs to change his password, his current one isn't forbidden (if it's in compliance with the current ...
5 votes
1 answer
23k views

What is meant by '550 Relay not Permitted' when it comes to emails?

For the past few months, I have been emailing a company with no problems. They have been able to receive my emails and they have been responding. A few days ago, they dropped me an email where my ...
0 votes
1 answer
311 views

Fixing a server that has been listed an Email Spam [duplicate]

Full Disclosure: Setup of email servers is something fairly new to me, so go easy on me :) Recently users reported that they were not receiving emails from my site. The site runs a vbulletin forum so ...
11 votes
2 answers
23k views

Where to place Nginx IP blacklist config file?

I have an Nginx web server hosting two sites. I created a blockips.conf file to blacklist IP addresses that are constantly probing the server and included this file in the nginx.conf file. However ...
1 vote
1 answer
461 views

How does Bind9 work as a private DNS, to get past URIBL Query Refused?

If queries to URIBL are blocked because URIBL "detects" that your DNS query is using a dns resolver ip address that has already made too many queries and exceeded the limit... How does using a LOCAL ...
1 vote
1 answer
1k views

iptables blacklist empty User-Agent sip tcpdump

I scan using tcpdump for user-agents that hit my phone server. I get interesting results. i add them to a list that protects alot of my servers out there. This works good. The problem is I get ...
0 votes
1 answer
741 views

Postfix sender blacklist

I'm running my own mail server (Ubuntu, Postfix, MySQL, Dovecot, Amavis, SpamAssassin, ...) since years for my family's mailboxes (5 mailboxes in total). I always try to improve my antispam filters. ...
0 votes
0 answers
587 views

How do I get my server off the ivmSIP blacklist?

On March 22nd I was notified by MX Toolbox that my server ip was blacklisted by ivmSIP and Hostkarma Black. I was aware of an attack some of our clients sites had suffered towards the end of January ...
0 votes
1 answer
7k views

Rejected - TRUSTmanager (in reply to MAIL FROM command)

After changing an IP address of email server (Postfix stack) I've found host that denies email message with: hostname postfix/smtp[38212]: 1AF542406D0: to=<[email protected]>, relay=xxx.xxx....
10 votes
5 answers
53k views

How to report spam to blacklists

Is there a central place to report spam to various blacklists ? I regularly report to spamcop, but I do not see the addresses I reported as listed. (I guess nobody else bothers with my regular ...
-3 votes
2 answers
3k views

How configure Postfix to check external blacklists?

How configure Postfix to block spam messages using external blacklists, like SPAMHAUS and BARRACUDA? Here my main.cf virtual_alias_domains = virtual_alias_maps = proxy:mysql:/etc/postfix/mysql-...
1 vote
1 answer
1k views

Remove AS that's falsely associated with our IP from email block list

When I try to send email from our email server to hotmail or outlook.com I get 550 5.7.1 Unfortunately, messages from [216.x.x.x] weren't sent. Please contact your Internet service provider since ...
1 vote
2 answers
550 views

Server IP blacklisted by RBL's

I'm using office365 mail for my domain Eg. "apples.com". The IP address is blacklisted, i think only the Microsoft support can de-list it from RBL's. Also after looking at the email header it looks ...
0 votes
1 answer
6k views

Blocking clients by IP using dynamic list in NGINX

I have a service using nginx as a frontend server. Some bots constantly bruteforcing /login page and it is sufficiently drops my server productivity. What I want to do is to count amount of login ...
1 vote
3 answers
5k views

IPTables add an IP to IPSet list

How to correctly add an IP address to ipset from an iptables rule? Or isn't that possible at all? This rule doesn't work for me: -A INPUT -m recent --name IP_LIST --set Type of IP_LIST is hash:net ...
1 vote
1 answer
5k views

Google detect mail as spam, server is not on blacklists, got 550-5.7.1 likely unsolicited mail

about two weeks ago I had security breach, one mail account on server, caused outgoing spam, I got listed in on couple blacklists rbl. Problem was fixed, IP was removed from all black lists. I can't ...
3 votes
1 answer
2k views

postfix not blocking blacklisted IP

I have a postfix/dovecot server running inside a docker container, and I would like to block some IP addresses from connecting to my SMTP server. I have the following in /etc/postfix/main.cf: ...
4 votes
2 answers
12k views

Gmail.com detect mail as spam, but the server is not on any BlackList

I have an issue with Google. (GMail to be exact) About 1 month ago, we had a security breach, and mail was relayed through our servers. we got listed in almost ALL Black-Lists :( we fixed the ...
0 votes
0 answers
386 views

How to block an IP for a specific site on a server with multiple sites

There's something hitting a server I'm looking at a rapid rate and it's taking the site down. It's doing ... POST /index.php/api/v2_soap/ HTTP/1.1, host: dev.mysite.com I'd like to block all IPs to ...