Questions tagged [blacklist]

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

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Why would a receiving mail server check the DNS A record of the from domain against a blacklist?

Most (all?) of the DigitalOcean network is currently listed on UCEPROTECT Level 3 (again). I know that UCEPROTECT Level 3 is widely regarded as shady and I personally recommend to our clients that ...
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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 ...
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Apache2 Blacklist ip based on x-forwarded-for header in virtualhost

I'm behind cloudflare dns and i'm trying to block specific client's ips that spams my website, i understood that i can achieve this by adding a SetEnvIf rule inside my virtualhost config that deny ...
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Auto block IP if request contains jndi

I have a VPS running CentOS 7 and I have very limited technical knowhow. However, given the recent log4j exploit, I need to do a few things. I've updated all software and packages on my server. I don'...
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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 ...
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Squid Proxy - Accepted wildcards in dstdomain lists

In my setup I have specific source IPv4 range whitelists and specific destination domain whitelists , both setup as separated whitelist files. Now I would want to have the possibility to limit the ...
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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 ...
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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 # ...
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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 ...
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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 ...
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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 ...
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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 ...
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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://...
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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:some@email.com: 550 5.4.1 Recipient ...
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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 ...
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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 ...
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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'...
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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 ...
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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 ...
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3 votes
1 answer
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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 ...
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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 ...
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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 ...
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1 vote
1 answer
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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 ...
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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. ...
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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 ...
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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 ...
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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=<user.name@domain.tld>, relay=xxx.xxx....
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2 votes
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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....
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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-...
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1 vote
1 answer
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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 ...
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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 ...
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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 ...
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2 votes
1 answer
1k 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: ...
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1 answer
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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 ...
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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 ...
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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 ...
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How can I remove my ip from the blacklist ivmSIP / 24?

I checked my server IP with this tool: http://www.mxtoolbox.com/SuperTool.aspx It has appeared in the ivmSIP / 24 list. What can I do to remove my IP from this list? I have SPF records set to allow ...
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How to allow only some IPs for the root of the website and all IPs for specific subset of URIs?

I have a website which is protected by Allow from IP filter but there is one specific subset of URLs which I would like to be open for everyone. dev.someweb.com should be available only from specific ...
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-2 votes
1 answer
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BlackList and WhiteList with windows server 2012r2 in Domain?

I'm trying to create Blacklist and Whitelist which dissallow or allow users in my domain installing certain softwares, programs. I just create a GPO in Company A OU, didn't modify anything. When I ...
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4 votes
2 answers
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Why is my mail server blacklisted (graylisting failiure)?

My mail server was blacklisted. I fail to understand why. It was first greylisted and than it became blacklisted. Greylisting is a practice of temporary rejecting mail coming from one mail server to ...
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1 vote
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Blacklisted by Sorbs only when my MUA in a specific network

I have: 2 networks A and B; 2 mail boxes abc@domain1.com and abc@domain2.com; destination xyz@gmail.com; a computer with MUA thunderbird. I'm in network A, send a mail from abc@domain1.com to xyz@...
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1 vote
1 answer
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552 user@domain is Black-Listed! in reply to Mail From command

For the last few days we are having some issues with few server we administrate. The remote servers are throwing the following error. 552 user@domain is Black-Listed! in reply to Mail From command ...
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How long DNS blacklist updates at Lotus Domino?

As I kown,for performance,Lotus Domino will get the DNS blacklist from the DNS blacklist sites and save it in memory. So,it is not real time? For example: 2016/08/30 09:37:46 SMTP Server: ...
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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 ...
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2 answers
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Blacklisted client: why did Postfix not reject this email?

Answer The best answer was on the postfix-users mailing list and it is summarized here for the benefit of serverfault's users. I had forgotten soft_bounce = yes. Always switch it back to no after ...
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SMTP Mail delivery failed for URIBL query refused

I'm experiencing some trouble with a single recipient because his mail server refuse my email. This is the error reply: SMTP error from remote mail server after RCPT TO:<xxxx@xxx.xxx>: 554 5.7....
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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 ...
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2 answers
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Business partner's IP in China is blacklisted so cannot email me

A business associate of ours out in China who we have been working with for over 5 years is now struggling to email us in the UK.. he is receiving the following error: Your message to .... was ...
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-1 votes
2 answers
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External Relay Server when server is on Blacklist

I have a Server with Cpanel , that is in a network with Blacklist (no way to change the Ip , all dirty ) , what i want to do , is install another server in another network that all emails sended can ...
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Mail getting blocked as abuse, error 500 [duplicate]

we just moved our domain ( daytonaparts.com ) to a new service provider ( ait.net ) and since we went live we have had our emails rejected by AT&T and Microsoft ( Hotmail, MSN, Live.com ) with an ...
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