Background
Clients get rightly frustrated with email delivery, especially if they get a rejection notice from a SPAM blocking service. Unfortunately on a shared server there is not a 100% guarantee all the time of email delivery.
Three reasons why shared servers get blacklisted
Here are three reasons why email delivery might be affected on a shared server:
1. Shared servers have 100s of mailboxes on them and one single one could be compromised. When this happens the spammer use scripts to start sending 1000s of emails. We block low thresholds for normal users, but even if there are just a few bounces the foreign system might pick it up and the server’s IP address will get listed.
2. Another issue with human issues are that any person can go and quickly download a poorly designed template from the internet. They could then use this template to and send email to all of their contact via our server. In this example because the template is poorly designed numerous systems will think it’s spam and automatically report it as such.
3. The third example is that of false positives. It’s entirely possible during the normal course of email sending that a receiving party has a grudge against the sending party and indiscriminately start marking origin messages as SPAM. If you do this enough to Google or Microsoft or in fact most systems, the bots won’t know what to do and would often err on the side of caution.
Vander Host Methodology for Server Delisting
Many of the blacklisting services you can’t just phone up and say delist – they are run by bots – so you have to wait or work on plan B.
Vander Host has numerous systems in place to mitigate these kinds of attacks and pro-actively responds when a client informs us of any kind of email issue. We can mitigate individual IP issues once our early warning systems or clients alert us. There is nothing unstable or unreliable about our service, rather the nature of the internet is people SPAM and ISPs have to work hard to fix the problem when it happens, especially on shared servers.
Early Warnings Systems and SPAM Mitigation
On the Vander Host network each and every email server’s mail queue is being monitored. Early warnings threshold are set sensibly to avoid false positives. We have a global monitoring system that plots these queues, and engineers and management are made aware of spamming incidents. We also attached SMS notification if any of the queues breach.
It still remains a challenge, because, there are at least 309 blacklist services on the Internet, and as mentioned some of them, including the most obscure ones, are run by robots. One of the most amazing services we use is MultiRBL, and here is the link: http://multirbl.valli.org
So what is the solution? Is shared hosting problematic?
Shared hosting is a great service. It’s the most cost-effective email and web hosting service available to end-users. We do however recommend that if a client is running a dedicated application, especially one that requires bulk or dedicated email services, they get their own VPS. All VPSses come with their own dedicated IP addresses. As an alternative we can supply for a fee an IP address with a shared hosting service. This isn’t very cost-effective because there is a limit on how many shared IPs can realistically be set on a shared server.