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We are running our mail servers on VPS and frequently get listed in a spam black list. Our clients began to complain about mail sending failures. (Mail is rejected by the recipients.)

The reason to be listed in the black lists is that, some others running VPS on the same provider are sending spam.

I searched the Internet to find another VPS hosting and saw that many other VPS hosting firms have bad reputation and get blacklisted. Is there a workaround for this?

4 Answers 4

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Your IP can be listed in blacklists even if your IP is dedicated. Using a shared IP doesn't necessarily impact your IP reputation as long as your neighbors have good behavior.

Usually IPs get blacklisted for various legitimate reasons, the most common of them are spam, phishing and/or malware.

If you think your IP is dedicated the first thing you should check is if your VPS is sending spam. It may be doing so even if you are not aware of it.

How you can check this depends entirely on how your server is set up. Most webservers have tools for checking the outgoing mail queue.

If you use cPanel or any server using Exim you can use this script which is really helpful for knowing if your server is sending spam and where is it coming: https://github.com/mdscunningham/shell-scripts/blob/master/spamfu.sh

Once you rule out this and fix the underlying problem (if any) you most certainly can request a delist from the blacklist provider in which your IP is in.

The most reputable providers let you delist your IP fairly easy and with very little steps.

If your server is listed in a blacklist that request money for delisting, don't pay any attention to it. Those providers are usually not trustworthy and only 1% or less of the internet use them.

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If this is happening your VPS must be using a shared IP address since that is what is used on spam lists. One solution is to get a dedicated IP address. Your hosting service should be able to provide one, usually for a monthly fee - if they can't, shop around for a new host.

Another solution is to get a dedicated server that has its own IP address.

Or you can purchase an IP address, however IPv4 addresses are in short supply https://en.wikipedia.org/wiki/IPv4_address_exhaustion

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  • I did a "reverse IP" search to find if another domain is hosted on the same IP but it does not give any other domain. Is there any other way to check If my IP is shared. Another question I use ssh to connect that VPS. Like "ssh root@IP" If several customers share that IP, how I can log into my server with ssh?
    – new_x
    Commented Sep 17, 2023 at 18:51
  • Ask your hosting company if it is a shared IP. If you have your own IP address for the VPS, and you keep ending up on spam lists, there must be a reason for that. I have a web hosting business with lots of customers and the only time the server ever ends up on a blacklist is if someone's wordpress site or mail account are compromised and there is a spam event.
    – Steve
    Commented Sep 17, 2023 at 22:36
  • @Steve Tjats not right. Large parts of IP space are mapped out as being end user IPs and are in blacklists, and thrre are blscklistd that mark out ranges which inclide dodgy IP"s. I also don't see how a dedicated VPS can run a shared IP address. AKA - in tje general case if you have root and a VPS and a static IP you must be able to control the SMTP server and thus its nit shared with others.
    – davidgo
    Commented Oct 13, 2023 at 17:58
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The only work-runarounds - if you can call them that - is to find credible providers who have no tolerance for spam and host with them.

Another interrelated strategy is to acquire your own IP address space (ie not a single IP - a minimum of a class C, but whatever is required to get control of the environment. This is fairly expensive and only really works if you are a big player.

That said, are you sure you are being blacklisted, rather then just having established a low quality reputation and being rate limited/having your emails classified as spam because you are not following enough best practices?

Email delivery is very specialist and there are a raft of things you need to do - and reading between the lines you seem unaware of these things. (One of the obvious ones is that forward and reverse DNS need to match - something I get the impression you are not aware of).

I point out that (for the general case) you can only run 1 mail server (ie SMTP server) per IP address - so if you have control of port 25 on a dedicated IP address no other party is sharing that IP address with you for sending mail. [ This is not to say that you are not being blacklisted because your VPS is in a bad neighbourhood ].

A workaround is to not do your own email hosting and rely on a specialist SMTP provider and relay your mail through them. This pushes the burden of reputation onto them.

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This question is broad and demands more information to be answered.

  1. If you "frequently get listed in a spam black list" maybe your clients are the spammers.
  2. Check if provider has reverse DNS on your IP and your PTR record is published.
  3. Make sure your DKIM, SPF and DMARC records are properly setup.
  4. Does your email server's configuration have a FQDN ?
  5. Finally, are you using an ISP that has strict spam policies ?

You can check if all your records are valid by using this tool here.

Also, you can check your email score here and correct any problems that may be reported.

There is no provider that can guaranty your IP will not be blacklisted, although there are some with hardened spam policies, it is up to you to maintain reputation regarding your domain(s) and IP address. And if your clients abuse your server, then look no further.

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