Anti-Spam Filtering Service - Email Security by MX Guarddog (2024)

Lets take a look at how you can protect your email server from direct delivery spam when you're on a shared hosting server and sharing compute resources with other customers.

Hosted Email

The majority of Internet domains are hosted on shared servers, usually with control panels such as cPanel, Plesk or Direct Admin for management. This is a very low cost solution and works great for small organizations that need hosting and email services.

The Drawbacks

There a few drawbacks with shared hosting solutions. They generally don't come with any anti-spam or anti-virus protection - if they do it is usually seriously lacking, allowing a large portion of spam to reach your inbox.

Another drawback is you don't have access to a firewall so you can't restrict who can connect to your server. This can cause issues for both your email server and your website - with hackers and spammers sending spam and trying to compromise your server.

Direct Delivery

How can you restrict access to your email server, even though you don't have a firewall? You can hide it! Your domain publishes a list of MX records, which tell other email servers where to deliver your mail - the servers listed in your MX records are responsible to receive your mail.

Often, the MX records for a domain on a shared hosting server will just be a single server... something like this:

By pointing your MX records to MX Guarddog's servers, we filter your incoming mail and deliver all clean mail to your server. After activating MX Guarddog your MX servers might look something like this:

By using MX Guarddog you are taking one step towards hiding your server. With our servers being used as your MX records it reduces the surface area a spammer, virus or hacker can reach your server.

We are seeing an increasing amount of spam that is delivered via direct delivery - or a direct delivery attack as we call it. Spammers ignore your MX records and try and find your email server by connecting to common names like:

If you are on a shared server, odds are good they will be able to establish a connection and deliver their spam direct to your inbox - without their messages being scanned for spam for virus infection. You need to protect your server.

Direct Delivery Prevention

On our direct delivery page we describe how you can protect yourself, including such things as limiting access to your server using a firewall, creating rules in Microsoft Exchange and changing your email server port.

These solutions are powerful in the fight against spam and virus attacks but all require you to manage your own server and are simply not available on a shared server - that sucks!

Direct Delivery - A Solution

On our direct delivery page one of the suggestions is to change your name. What we mean by that is changing the name of your server(s).

If spammers lookup the name of your server, often, you can change the name to something else. If you were to change the name of your server (the DNS A record) to when the spammer attempts to lookup their lookup request will fail and they will not be able to locate the address of your server - they can't find a route to your email server! They have been prevented from a direct delivery attack - success!

Anti-Spam Filtering Service - Email Security by MX Guarddog (1)It is not possible to get rid of, if you did no users would be able to connect to your website. You could use a service such as CloudFlare which is designed to improve the performance of your website and stops hackers from harming your website. If you are using CloudFlare no spammer, virus or website hacker will be able to find the true IP address of your website - they can't find a route to your email server - success!

Making Changes

The topics discussed above are fairly simple, but if you are new to networking or don't fully understand the changes required in your DNS servers you may need to seek assistance to make these changes.

If you rename your server, don't forget to update the your email servers page at MX Guarddog or we will not know where to send your mail. Any legitimate user or service will also need to change the name they use to access your server.

Implementing these changes will keep spammers away from your server but will also keep MX Guarddog from reaching your server if you don't inform us where to send your mail.

A Hosted Email Alternative

Anti-Spam Filtering Service - Email Security by MX Guarddog (2)If renaming your server is not possible and you may want to consider Zoho Mail.

At the time this article posting (June 2016) Zoho is the only shared hosting service that we know of that allows you to create a firewall.

Updated 2016/06/14

Anti-Spam Filtering Service - Email Security by MX Guarddog (2024)


How to fix 550 5.7 1 This message is rejected by our spam filters? ›

  1. From the Exchange program group:
  2. Open the Exchange Management Console. ...
  3. Open the Content Filtering Anti-Spam filtering type and go to the Action tab.
  4. Then uncheck the box next to "Reject messages that have SCL rating greater or equal to:"
Mar 20, 2023

What is the best free email spam filter? ›

INTRODUCING MAILWASHER: The leader in spam filter software, and the easiest way to check and manage your e-mails before you download them to your computer. Over 8 million people use MailWasher as their spam filter! MailWasher is free to use and won't ever expire.

What do you mean by spam filtering methods in email? ›

Spam filters are designed to identify emails that attackers or marketers use to send unwanted or dangerous content. They use specific filtering methods to identify the content of emails or their senders and then flag the email as spam.

Do spam filters open emails? ›

Sometimes, recipient spam filters may click-through links in emails to verify that they are safe for the receiver of the email to click on. This is good because spam filters are doing their job and protecting recipients.

How do I fix email error 550 5.7 1? ›

Specific Solutions for Popular Email Services
  1. Verify Sender Authentication Records. SPF (Sender Policy Framework). ...
  2. Ensure Email Address Authorization. ...
  3. Correct SMTP Settings in Email Client. ...
  4. Check for IP Blacklisting.

How do I fix error 550 on my email? ›

Easy Ways To Troubleshoot a 550 Blocked Error
  1. Double-check the recipient's email address. ...
  2. Confirm with the recipient that you have their correct email address. ...
  3. Check your own email address and message. ...
  4. Try changing your outgoing mail port to 26 or 465. ...
  5. Scan your computer for viruses and malware.

Is there a 100% free spam blocker? ›

Hiya - Caller ID & Block - Best Android Spam Blocker

Hiya is easy to use and it is free.

How do I stop spam emails permanently free? ›

Thankfully, there are steps you can take to help prevent spam emails from ending up in your inbox:
  1. Mark as spam. ...
  2. Delete spam emails. ...
  3. Keep your email address private. ...
  4. Use a third-party spam filter. ...
  5. Change your email address. ...
  6. Unsubscribe from email lists.

What is the least hacked email provider? ›

7 Most Secure Email Providers
  1. Proton Mail. Price: free with up to 1 GB of mail storage or $12.99 a month for Proton Unlimited. ...
  2. Neo. Price: starts at $2.49 per mailbox per month with 10 GB of storage. ...
  3. Hushmail. ...
  4. Tuta (formerly Tutanota) ...
  5. StartMail. ...
  6. Mailfence. ...
  7. Zoho Mail.
Jul 1, 2024

What triggers spam filters in emails? ›

Your reputation as an email sender, along with your contacts' engagement with your emails, can affect it. If your emails consistently have poor engagement, such as low opens or high bounces, filters may adapt to that and start delivering your email to the spam folder.

How do I turn off email filtering? ›

See all settings.

Click Filters and Blocked Addresses. Find the filter you'd like to change. Click Edit or Delete to remove the filter. If you're editing the filter, click Continue when you're done editing.

What is the difference between phishing and spam emails? ›

Spam is unsolicited email, instant messages, or social media messages. These messages are fairly easy to spot and can be damaging if you open or respond. Phishing is an email sent from an Internet criminal disguised as an email from a legitimate, trustworthy source.

Do spam emails know if I open them? ›

Scammers will be able to tell that you opened an email if you download any attachments or click on any links (which you should never do), or if your email client automatically loads any images that are embedded in the message.

How do I get my emails to stop going to spam? ›

12 Tips to Stop Your Emails From Going to Spam
  1. Build your own email list.
  2. Provide a double opt-in.
  3. Authenticate your email.
  4. Clean up your email list regularly.
  5. Avoid email denylists and monitor your reputation.
  6. Be compliant with internet privacy laws.
  7. Provide an email preference center.
  8. Monitor your email engagement metrics.
Apr 11, 2024

What is the best spam filter for email? ›

Top 15 Best Email Spam Filters Available in the Market
  • SpamTitan for Individuals. ...
  • Zoho Mail. ...
  • ProtonMail. ...
  • SpamTitan for Businesses. ...
  • Proofpoint Essentials. ...
  • Mimecast. ...
  • Barracuda Essentials. ...
  • Cisco Email Security.
Apr 3, 2024

What is 550 message rejected due to spam policy? ›

This error message appears because a part of your email may contain words that trigger the spam filters or the recipient mail server classifies your message as spam. Spam filters usually check for red flags, such as: Emails without an unsubscribe link.

What is 550 5.7 1 access denied to? ›

Typically, this error indicates a security setting in your organization or the recipient's organization is preventing your message from reaching the recipient. For example: You don't have permission to send to the recipient.

What is 550 5.7 1 rejected virus detected? ›

If you're receiving this error, it means we have detected abuse originating from your email account. It is likely that your account is compromised or forwarding spam or attack email at a very fast rate. It also means that the receivers do not like the content of the mail that is being received and are rejecting them.

What does 554 5.7 1 message has been rejected due to suspected spam content? ›

Common culprits of the 554 5.7.

Well, email servers can blacklist entire IP addresses (like your internet address) if they're associated with sending spam. If you fall into this category, your emails might get flagged and rejected.

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