How To Resolve Problems When Sending Email

If you’re having problems sending email, it may be something as simple as a wrong password or a port being blocked. Here are some common reasons you may have issues sending email.  Please see below for useful troubleshooting steps, ideas, and related articles.

Wrong Password

Even if you’re absolutely sure the password was entered right, it is worthwhile to check again. If you’re thinking “It has to be right, because I copied and pasted it” you might be surprised. Many times, especially in Firefox and certain other applications, when you paste in the password an extra space will be inserted. One blank space may be added to the end of your password so it is advised to copy and paste this into a Notepad file before copying and pasting. If you have webmail access, try logging into webmail with your username and password in order to test and make sure you are using the right username and password.

Secure Connections and Ports

Some email service providers require the use of a secure connection in order to connect to SMTP. You need to make sure this option is selected in the email client you’re using. For example, in Outlook, there’s an option for “This server requires a secure connection”.

Some servers may also require connecting on port 465 (secure) vs 25 (insecure). If neither of these ports work, you can also try port 587.

Speaking of Ports….Port 25

Many ISPs will have port 25 blocked. So if you’re trying to use port 25 and are not able to send email, you may want to try using another port when sending emails.

Check For Open Ports

For Windows

Hit the Windows key+R and type in cmd to bring up the command prompt box. Then, type in:

telnet 25

For Mac

  1. Go to Mac HD
  2. Go to Applications
  3. Go to Utilities
  4. Open Up Terminal
  5. Type this and hit enter:

For Linux

Using a terminal, execute this:

telnet 25

If you get a message that has 220 in it or “connected” then it should open and ready to use. But if you get an error, couldn’t connect or no response at all then it’s blocked.

Hold CTRL + } and then type q and then press ENTER to end a telnet connection


If you see an error that mentions authentication then you may have the wrong authentication method setup. Most email programs provide different options for password authentication, including:

  • Encrypted
  • Kerberos
  • Normal or plain text

Try using normal or plain text if you are having any trouble setting up your email client access in cPanel

SMTP Crash

If you see an error that mentions something about server unknown, make sure you have the servername correct and there’s no problem with the resolution of the server.

Ping the server

  • If it responds to the ping, it’s the mail server not responding
  • If it doesn’t ping either, the entire server is not responding and rebooting may help
  • If it doesn’t resolve at all, it’s likely something wrong with the DNS of the domain/host – look it up on

How To Acquire Your MX IP and Ping

Typically, within our Shared and Business shared services, your MX IP will be that of your dedicated IP provided.  However, it’s best to confirm this or see if its different by running the following checks.

Step1:   At a command prompt, type nslookup, and then press ENTER.

Step 2:  Type server <IP address>, where IP address is the IP address of your external DNS server, and then press ENTER.

Step 3:  Type set q=MX, and then press ENTER.

Step 4:  Type <domain name>, where <domain name> is the name of your domain, and then press ENTER. The MX record for the domain you entered should be displayed.

If your test comes back with your domain without, this typically means the dedicated IP shares the same IP with your MX mail server.  Otherwise, the test will comes back with alternative IP related to

Now run a standard ping test within command prompt to that IP to check connectivity.


You can also ping for further investigation if you are pointing your MX record to


Your IP may have been blacklisted. Use one of these blacklist checkers to see if your server or IP has been blacklisted:


You may be sending SPAM whether you realize it or not. Please contact our support team to request your email logs and email activity be reviewed if you feel that this is a possibility.

Mail Queue

The mail queue may be full or stopped. You only have access to this through WHM though.

  1. Go to WHM
  2. Go to Mail Queue Manager under Email

Here, you’ll be able to view emails that are in the queue and see how many there are. You can also attempt to deliver undelivered messages that are sitting here. If an attempt was made to send an email to an incorrect/unavailable address, they’ll be here. You should manually delete these emails to clear them out.

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