How to check whether your outgoing mail server is blocked?

Using a dedicated server for those websites who are having high web traffic is one of the best options. And the reason behind it is that by using dedicated servers you get more resources when compared to shared or Virtual Private Server. Not only that you can also easily manage your website as per your requirements.  Using a dedicated server for your website gives you more reliability, flexibility and also security. So today most of the people also use email service on their dedicated server and today email plays as an important mode of communication in all the field.



So today if you are using a dedicated server for your website and also using mail service along and if you are not able to send the mail or if you want to know whether your mail server is blocked or not then here is the solution. Today most of the mail services are using port 25 for SMPT to send out emails. But sometimes your ISP- Internet Service Provider may block port 25 in order to prevent spamming by its customers or in case if you are sending any spam emails. That is when you will not be able to send any emails to your customer or clients.


Here is the information on how to check whether your outgoing mail server( Port 25) is blocked or not on your network.:


>> Log into your SSH/ Root access


>> Enter the following command:


telnet 25


>> Now you will see the following results-

If your port 25 is not blocked you will get a  strong 220 response



Connected to

Escape character is '^]'.

220 ESMTP Exim 4.63 Tue, 10 April 2010 10:04:04 -0900


Now if the port 25 is blocked then you will get a connection error or no response message-



telnet: connect to address Connection refused

telnet: Unable to connect to remote host


>> So now if your port 25 is blocked then you can choose to use the alternate Port 587


>> You can also use this same technique to check if Port 587 is blocked as well.  All you need to do is insert this command:


telnet 587


Blocking the Emails on Linux


If you are getting continuous emails from any email id which is not relevant to you then you can make use of our Filtering module named Account Level Filter which allows you to filter emails that are sent to your domain’s email accounts.


It creates a new email which will receive those emails that have been filtered out, this email address cannot be used to send mail.


Certain Rules needs to be followed which is nothing but the conditions specified to filter the Emails. The patterns or keywords specified in the rules will be checked against the incoming mail and if it matches the action specified in the rule will be taken.


Let's have a brief steps to create Account Level Filter by following the Rules:


  1. First you need to Login to our WHM Panel.


  1. Under List Account Select appropriate user and click on login.


  1. In the Advanced section click on Account Level Filter Module.


  1. Now you will be able to see list of Filters which is present if created or using the form below create a new Filters.

a) Filter Name : Enter the name you want to give for this new filter.

b) Rules : Select any of the below drop down message characteristics type

From - address from which the message was sent.

Subject - the subject line of the message.

To - address to which the message was sent.

Body - content area of the message.

Any Header - an header of the message.

  1. Next Select the any of the  Rule operator from the drop down menu.

Contains - contains the string you defined.

Equals - it exactly matches the string which you have defined.


  1. Now You can see a blank box below the two drop downs, this is where you need to enter the string to be matched.


  1. Under Action you need to select Discard Message which will delete the mail with no failure message.


  1. Once All the above mentioned data’s are filled click on Save.



  1. If you want to delete the filter just click on delete button.