Test emails on Server with SMTP

You can check whether the port is open on a Server by using tcping.exe which you can download online. Tcping can also be similarly used to check other ports on a Server.

Open Powershell or Command prompt in Admin mode and then type the following command:

tcping smtp.some.domain 25

Port 25 is usually the default port for SMTP communication between mail servers.

You can also telnet to test out this port. Telnet should be enabled on your machine.

telnet smtp.some.domain 25

You can send a test email using Powershell using the below command:

Send-MailMessage -From 'Test User1 <test.user1@test.com>' -To 'Test User <test.user2@test.com>' -Subject 'Test mail' -SmtpServer 'smtp.some.domain'

TELNET to test connection to POP3/IMAP

First, make sure TELNET is installed on your machine else you’ll get error. You can install TELNET through Add or Remove feature on Windows.
You can use TELNET via a command prompt to confirm.

For IMAP check port 143 and if using SSL then check port 993.

For POP3 check port 110 and if using SSL then check port 995.

Test POP3 connection:

  • Start a command prompt
  • Enter TELNET {webserver} port e.g. TELNET exchangesrvr01 995
  • Enter USER {login} e.g. USER testemail@mycomp.com
  • Enter PASS {password} e.g. PASS secret
  • Enter LIST to show the mailbox
  • Enter QUIT to Exit

At each stage you should receive an OK message. If there is an issue at any stage you will receive an error

Test IMAP connection:

  • Start a command prompt
  • Enter TELNET {webserver} port e.g. TELNET exchangesrvr01 143
  • Enter . LOGIN {login} {password} e.g. LOGIN testemail@mycomp.com secret
  • Enter . LIST “” “*” to show the mailbox
  • Press CTRL + ] and then QUIT to Exit

At each stage you should receive an OK message. If there is an issue at any stage you will receive an error.