How to Test SMTP AUTH using Telnet
Below are instructions on how to test SMTP AUTH against a mail server using Telnet and entering the commands by hand.
The first thing you need to do is get a base64 encoding of your username and password. There are a couple ways to do this, the example below uses Perl:
perl -MMIME::Base64 -e 'print encode_base64("username");' perl -MMIME::Base64 -e 'print encode_base64("password");'
What will be returned from each command is a base64 encoding of the username and password; save these as you will need them later. Now connect to the mail server using Telnet:
telnet mailserver.com 25
Greet the mail server:
EHLO mailserver.com
Tell the server you want to authenticate with it:
AUTH LOGIN
The server should have returned 334 VXNlcm5hbWU6;
this is a base64 encoded string asking you for your username, paste the base64 encoded username you created earlier, example:
dXNlcm5hbWUuY29t
Now the server should have returned 334 UGFzc3dvcmQ6;
. Again this is a base64 encoded string now asking for your password, paste the base64 encoded password you created, example:
bXlwYXNzd29yZA==
Now you should have received a message telling you that you successfully authenticated. If it failed your user/pass may have been wrong or your mailserver is broken.
Below is a log of a real successful SMTP AUTH connection over Telnet:
user@localhost [~]# telnet exampledomain.com 25 Trying 1.1.1.1... Connected to exampledomain.com (1.1.1.1). Escape character is '^]'. 220-server1.exampledomain.com ESMTP Exim 4.66 #1 Wed, 09 May 2007 23:55:12 +0200 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail. EHLO exampledomain.com 250-server1.exampledomain.com Hello [1.1.1.2] 250-SIZE 52428800 250-PIPELINING 250-AUTH PLAIN LOGIN 250-STARTTLS 250 HELP AUTH LOGIN 334 VXNlcm5hbWU6 dXNlcm5hbWUuY29t 334 UGFzc3dvcmQ6 bXlwYXNzd29yZA== 235 Authentication succeeded
번호 | 분류 | 제목 | 글쓴이 | 날짜 | 조회 수 |
---|---|---|---|---|---|
189 | System/OS | [linux] 패킷의 소스 주소 바꾸기 | hooni | 2003.04.23 | 18870 |
188 | Develop | URI 인코딩, URL 인코딩 | hooni | 2013.04.23 | 18907 |
187 | System/OS | [mac] 컨텍스트(Context) 메뉴 "다음으로 열기" 내용 정리 | hooni | 2013.07.10 | 18909 |
186 | Develop | 모터에 대한 pid 제어.. ㅎㅎ | hooni | 2013.04.23 | 18942 |
185 | System/OS | [linux] APM(apache, php, mysql) + gd 설치순서.. | hooni | 2003.04.23 | 18951 |
184 | System/OS | 나중에 해봐야지.. libconv 설치.. ㅡ,.ㅡ; | hooni | 2013.04.23 | 19345 |
183 | System/OS | [mysql] MySQL server has gone away 에러 대응 | hooni | 2013.05.29 | 19394 |
182 | Etc | 정보시스템(정보보안)의 위험관리 설명 | hooni | 2013.04.23 | 19409 |
181 | Develop | [js]모바일 웹에서 orientationchange | hooni | 2013.04.23 | 19432 |
180 | Develop | [php] XE 에서 php 구문 사용하기 (XE 템플릿에서) | hooni | 2013.10.31 | 19546 |
179 | Etc | [세미나] XML 레포트.. | hooni | 2003.04.23 | 19789 |
178 | Etc | 양성/음성 오류에 대한 개념 | hooni | 2013.04.23 | 19916 |