Verify SMTP configuration from Cmd Prompt using TELNET
NOTE: Type the commands to be entered in notepad and then copy paste it. Using Backspace/Delete/Insert/Editing in Cmd prompt creates incorrect result.
Step 1:At command prompt, type: telnet <smtp_Server> <port>
Ex: telnet mail.mailserver.com 25
Step 2:Type EHLO , and then press ENTER.
Goto Step 6, if Authentication is not required:
Step 3:Type AUTH LOGIN. The server responds with an encrypted prompt for your user name.
Step4:Enter your user name encrypted in base 64. You can use one of several tools that are available to encode your user name.
Step 5:The server responds with an encrypted base 64 prompt for your password. Enter your password encrypted in base 64.
Step 6:Type MAIL FROM:, and then press ENTER. If the sender is not permitted to send mail, the SMTP server returns an error.
Step 7:Type RCPT TO:,and then press ENTER.If the recipient is not a valid recipient or the server does not accept mail for this domain, the SMTP server returns an error.
Step 8:Type DATA.
Step 9:If desired, type message text, press ENTER, type a period (.), and then press ENTER again.
If mail is working properly, you should see a response similar to the following indicating that mail is queued for delivery:
250 2.6.0 email@example.com