SMTP Telnet Test

We are standing up a new data center and users received SMTP errors while testing. We were able to ping the server so DNS lookup and network traffic was working. But we only had a generic SMTP error message. So, I fired up telnet and tested our SMTP connection using these commands:

telnet
o smtp.psadmin.io
ehlo
mail from:ps@psadmin.io
rcpt to:user@psadmin.io
data
Test Email
.

When we first tested send emails through the SMTP server, we received an “Unable to relay for user@psadmin.io” error. That’s much more descriptive and a useful message to send to the Exchange administrators.

Tags:

Leave a Reply

Your email address will not be published. Required fields are marked *

To create code blocks or other preformatted text, indent by four spaces:

    This will be displayed in a monospaced font. The first four 
    spaces will be stripped off, but all other whitespace
    will be preserved.
    
    Markdown is turned off in code blocks:
     [This is not a link](http://example.com)

To create not a block, but an inline code span, use backticks: 

Here is some inline `code`.

For more help see http://daringfireball.net/projects/markdown/syntax