First connecto to the server. It’s usualy on port 25 but this can change from server to server:
telnet server.com 25
Then say hello:
EHLO server.com
Say you will be providing plain auth:
AUTH LOGIN
The server will ask you for your username (it replies 334 UGFzc3dvcmQ6 which is 334 Username: encoded in base64). Then give you base64 encoded user name. You can use this web to encode it: http://www.base64encode.org/
dXNlcm5hbWU=
Now the server will ask you for your password (it replies 334 UGFzc3dvcmQ6 which is 334 Password: encoded in base64). Give your base64 encoded password:
cGFzc3dvcmQ=
It should anser something like this:
235 Authentication succeeded
Now send the email as usual:
MAIL FROM: RCPT TO: DATA Subject: Hello Your message .
Note: If you supply an email subject you have to press enter twice before starting with the actual message.
This is how it should look everything together:
$ telnet server.com 25 Trying 97.53.12.9... Connected to server.com. Escape character is '^]'. 220-server.com ESMTP Exim 4.80 #2 Wed, 12 Feb 2014 13:37:51 +0100 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail. EHLO server.com 250-server.com Hello 32.92-10-25.blabla.tururu.com [92.10.25.32] 250-SIZE 52428800 250-8BITMIME 250-PIPELINING 250-AUTH PLAIN LOGIN 250-STARTTLS 250 HELP AUTH LOGIN 334 VXNlcm5hbWU6 dXNlcm5hbWU= 334 UGFzc3dvcmQ6 cGFzc3dvcmQ= 235 Authentication succeeded MAIL FROM: 250 OK RCPT TO: 250 Accepted DATA 354 Enter message, ending with "." on a line by itself SUBJECT: Hi! Test . 250 OK id=1WDZ6R-0008KT-Nx
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