Icelab Networks Knowledge Base

Cannot Send Email

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There are a few reasons why you might not be able to send email.

1. The most common cause for customers who are unable to send email is a personal firewall or anti-virus software running on your computer which suddenly begins interferring with your email client software. Usually this issue can be resolved using one or both of the following steps:

A. Reboot your computer

B. Turn off your personal firewall and/or antivirus software, then try to send a message

C. Open your email client software and remove all of the messages in your Outbox

2. Your ISP could be blocking SMTP port 25 in an attempt to control spam originating from its network. If you believe this is the case, you will need to run the following test to verify, or call your ISP to ask them if they block SMTP port 25.

Windows XP

Click start, then run. Type 'cmd' in the run box. A command prompt will open. Type the following command:

telnet mail.yourdomain.com 25

Windows Vista and Windows 7 (telnet must be installed to run this test!)

Click Start. In the search bar type 'cmd'. A command prompt will open. Type the following command:

telnet mail.yourdomain.com 25

Mac OS

Open the Terminal application. You will find the Terminal application in the Applications folder. At the command prompt type:

telnet mail.yourdomain.com 25 (replace 'yourdomain.com' with your actual hosted domain name)

The telnet test should print a banner that reads "220 server.domain.com ESMTP". If it prints nothing, or if it hangs then it means either your computer, local area network, or ISP is blocking SMTP services. You should contact your network administrator or IT department for further assistance.

If your ISP is blocking SMTP services, ask them for an outgoing email server that you can use to relay email. They will walk you through setting up your outgoing email.