Sometimes after setting up an email client, you will be able to receive email but sending email will lead to an error message.  There are many different possible causes to this problem including the email client settings and port blocking.  One of the solutions listed below should help resolve your issue so that you can start sending email again.

Perform a Whois lookup

The WHOIS database is a public database that contains details about a domain, such as who it belongs to, and when it was last modified. When you lookup your Whois, the main thing you want to check for is the expiration date, to ensure it has not expired. If it has expired, you must renew the domain with your registrar, and point back to our Nameservers. Then within 24 hours it will propagate back to us, and restore functionality.

Client Configuration Settings

If you are not able to send email, first make sure that you are using the correct email settings in your email client:

  • SMTP Server: (replace with your actual domain name)
  • SMTP Authentication: Enabled
  • SMTP Username: (replace with your email address, all lowercase)

Port 25 blocking

If you cannot send email, one possible cause is your ISP (Internet Service Provider) may have blocked Port 25 which is preventing your email from being sent.  This feature can change without notice so if you previously were able to send email then this is the likely cause.

Here we have a few of the ISPs that have blocked Port 25, and their documentation related to the port being blocked:

Checking if Port 25 is blocked

The easiest way to find out if port 25 is blocking your email is to contact your ISP as they will be able to provide you with the information. For the advanced user, we've included directions below to test port 25 email blocking via the command line in Windows and Mac.

To test if port 25 is blocking your email, open your command line on your local computer. For windows users, you can access this via start -> run -> cmd. Mac users can use the "terminal" application. Once on the command line, type telnet 25. Telnet is disabled in Windows Vista and Windows 7, so first you will have to enable Telnet.  Visit the official Microsoft page for more information for enabling Telnet.  If you get no response or a failure, port 25 blocking is the likely reason your email is not being sent.

How do I connect to email if Port 25 is blocked?

If your ISP does block port 25, you can work around it in either of three ways: 

  • Solution #1

    As your ISP is blocking port 25, the best solution is to use the outgoing mail server provided by your ISP. To do this you would need to contact your ISP and ask what server they recommend.

  • Solution #2

    In addition to using Port 25, our servers also use Port 587 to run SMTP.  If 25 is blocked by your ISP, in your email client you can change 25 to 587 and see if you are able to send email.

  • Solution #3

    You can also use the secure, or SSL, port for outgoing email. This will involve selecting the setting "this server requires a secure connection (ssl)" in your email client. Once you check that box, then change the email port listing from 25 to 465 and save the changes. These settings are usually found in the advanced settings of your email client. Please see the end of this article for more details.

    You will also want to change the outgoing server name to, secure## being the secure alternative of the actual server you are on. For example, if your Welcome Email states that your account is on, your outgoing server name should be If you are unsure, please contact support.

How to update your SMTP port and SSL settings

In most email clients, the SMTP port and SSL settings are updated on the same settings page, and that page is generally in the advanced settings. The directions below will assist you in finding where to change these settings:

  • Outlook 2002 / 2003
  • Outlook 2007/2010/2013
  • Outlook Express
  • Mac Mail
  • Microsoft Entourage
  • Thunderbird
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2013-07-23 8:41 am
My email brings this every now I send mail: Message not sent. Server replied:

Requested action not taken: mailbox unavailable
550 This message was classified as SPAM and may not be delivered. For more
information, please see
7,075 Points
2013-07-23 3:15 pm
Hello info1965,

Thank you for contacting us. This message is typically displayed when you attempt to send an email out, that contains something that has been flagged as spam.

Have you tried any of the common fixes listed in the article you were linked to?
550 This message was classified as SPAM and may not be delivered

We are happy to help, but we need more information to provide a more specific answer, such as your email address, and the address you are sending to.

If you have any further questions, feel free to post them below.
Thank you,


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