The telnet application can be used to test your connectivity to our relay servers. If you are having difficulty in being able to connect to, it is typically a matter of trying a different port and confirming your username/password combination.

If you are using Windows, you can use our SMTP testing tool. Otherwise, a quick test using a language/application that supports SMTP can be used for troubleshooting. Note: the testing tool uses, not express-relay, but its results are still valid.

Here is an example using telnet, which is widely available on computers (see below if not). To get your Base64-encoded username and password values, go to
If my JangoSMTP username were MyJangoSMTPUsername, then the encoded value I would use after the “auth login” prompt would be TXlKYW5nb1NNVFBVc2VybmFtZQ==. Do the same thing to get your password encoded.


Ports: 25, 587, and 2525 for unsecure, and 465 for secure.

Using express-relay example – start with ehlo, not helo:

220 ESMTP Welcome to the JangoSMTP trackable email relay system.
ehlo Hello [], Haraka is at your service.
250-SIZE 31457280
auth login
334 VXNlcm5hbWU6
enter your Base64 encoded username
334 UGFzc3dvcmQ6
enter your Base64 encoded password
235 Authentication successful
mail from:enter your valid FROM address
250 sender <the address from above will be output here> OK
rcpt to:enter here
250 recipient < will be output here> OK
354 go ahead, make my day
subject:testing express-relay

250 Message Queued (4FEFB870-379A-45ED-A76C-B474AB3F6E71.1)
221 closing connection. Have a jolly good day.

Using old relay or

$ telnet
telnet> open 25
Connected to
Escape character is '^]'.
220 ESMTP Welcome to the JangoSMTP trackable email relay system.; Wed, 01 Feb 2012 17:40:28 -0000
250 Hello, pleased to meet you.
auth login
334 VXNlcm5hbWU6
Umxxxxxxxx (Base64 encoded username)
334 UGFzc3dvcmQ6
Mzxxxxxxxx (Base64 encoded password)
235 2.0.0 Authentication successful
mail size=100
250 2.1.0 <>... Sender ok
250 2.1.5 <>... Recipient ok; will forward
354 Enter mail, end with "." on a line by itself
subject:sending via telnet and jangosmtp username/pwd


Running telnet in Windows

The telnet client isn’t normally enabled in Windows (7, 8 and 10), but you can make it so via Control Panel > Turn Windows features on or off, and in the dialog window, scroll down and enable the telnet client (not the server). Open a new command prompt window and run your session.


Note that the message ID returned is from SMTP, not JangoSMTP, so this is not your transactional message ID. However, if you happen to have this ID and are working with Support to troubleshoot a sending/delivery issue, having this ID helps quite a bit given that we may have to search more than one relay server to find your session/transaction.