Today I had the request to test SMTP authentication against a HCL Domino Server on Windows and was too lazy to download, install and configure a mail client like Thunderbird or any alternative.

There’s a very simple way how to accomplish this request – here are the required steps:

1. Convert your login data to Base-64
Therefore just open a PowerShell window and enter the following command for converting your login name:

[System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes(“testuser@domain.com”))

When running this command for “testuser@domain.com” you should receive the following result: dGVzdHVzZXJAZG9tYWluLmNvbQ==

Then run the same command for your password – just replace your login name with the password. Now it’s just a recommandation to save the commands AND the results within a text file 😉

2. Login to your Domino Server from a Telnet session
> telnet server.company.com 25
> ehlo myname.company.com
> auth login
>>> enter the result from the first conversion ( your login name )
>>> now paste the result from the second conversion ( your password )
>>> you should receive the information that your are successfully authenticated
>>>>> 235 Authentication successful

Now you can go on with all other stuff ( mail from, rcpt to, data, … ) to send your email.