In order to test the mail services working properly, testing needs to be performed. Instead of using GUI mail client or webmail to test the sending and receiving email,you also can use telnet. Telnet is the most basic mail client. It does the same thing as advanced mail client such as Microsoft Outlook and Mozilla Thunderbird. Telnet will verify and check the server responses to mail requests that was typed.
Perform Testing for Posfix Mail Service using Telnet on linux shell :
[root@mail ~]# telnet localhost 25 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 mail.zimbra.local ESMTP Postfix Helo mail.zimbra.local 250 mail.zimbra.local MAIL FROM:<admin@zimbra.local> 250 2.1.0 Ok RCPT TO:<user@zimbra.local> 250 2.1.5 Ok DATA 354 End data with <CR><LF>.<CR><LF> Subject: My Test Email This is the body of the Email . 250 2.0.0 Ok: queued as 194869C1AB quit 221 2.0.0 Bye Connection closed by foreign host.
Perform Testing for Posfix Mail Service using Telnet on Windows Command Prompt :
C:\>telnet mail.zimbra.local 25 220 mail.zimbra.local ESMTP Postfix ehlo mail.zimbra.local 250-mail.zimbra.local 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-STARTTLS 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN MAIL FROM:<admin@zimbra.local> 250 2.1.0 Ok RCPT TO:<user@zimbra.local> 250 2.1.5 Ok DATA 354 End data with <CR><LF>.<CR><LF> Subject: My Test Email This is the body of the EMAIL Message! . 250 2.0.0 Ok: queued as 538BB9C1AD
Steps to Perform Testing the Postfix Mail Service
1. Establish a TCP connection to port 25 which is postfix port :
[root@mail ~]# telnet localhost 25
You should receive a 220 response:
Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 mail.zimbra.local ESMTP Postfix
Postfix is listening and we can communicate with SMTP now.
2. Next,greet the postfix server. The function is considered same with postman or transport :
Helo mail.zimbra.local
The postfix mail server should respond as below :
250 mail.zimbra.local
3. Inform the postfix server know who the sender is:
MAIL FROM:<admin@zimbra.local>
You will get ‘250’ output if the postfix accepts the sender address :
250 2.1.0 Ok
4. Specify the recipient of the email :
RCPT TO:<user@zimbra.local>
If Postfix accepts the recipient address will returned 250 response :
250 2.1.5 Ok
5. Send the actual Email with subject and body of the email :
DATA
Postfix agrees and feedback us to start actual email and returned this output :
354 End data with <CR><LF>.<CR><LF>
6. Start compose the mail, type the word ‘Subject:’ for email subject then enter. Type email body end our input with a dot.
Subject: My Test Email This is the body of the Email .
As before, if postfix agress and accepts the email, it will returned 250 response :
250 2.0.0 Ok: queued as 194869C1AB
7. Postfix test fixt telnet finished at the moment, So you can quit :
quit
221 2.0.0 Bye Connection closed by foreign host.
Trace the mail on Postfix Mail server using message ID :
On Linux shell, message id is 194869C1AB :
[root@mail ~]# cat /var/log/maillog | grep 194869C1AB Jun 5 01:58:21 mail postfix/smtpd[12285]: 194869C1AB: client=localhost.localdomain[127.0.0.1] Jun 5 01:59:24 mail postfix/cleanup[17117]: 194869C1AB: message-id=<20120604175821.194869C1AB@mail.zimbra.local> Jun 5 01:59:24 mail postfix/qmgr[4464]: 194869C1AB: from=<admin@zimbra.local>, size=409, nrcpt=1 (queue active) Jun 5 01:59:25 mail postfix/cleanup[17117]: 52A7E9C1AD: message-id=<20120604175821.194869C1AB@mail.zimbra.local> Jun 5 01:59:25 mail postfix/smtp[17317]: 194869C1AB: to=<user@zimbra.local>, relay=127.0.0.1[127.0.0.1]:10024, delay=73, delays=72/0.02/0.1/0.76, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 52A7E9C1AD) Jun 5 01:59:25 mail postfix/qmgr[4464]: 194869C1AB: removed
On Windows Command Prompt, the message id is 538BB9C1AD.
[root@mail ~]# cat /var/log/maillog | grep 538BB9C1AD Jun 5 02:14:08 mail postfix/smtpd[21232]: 538BB9C1AD: client=unknown[192.168.1.52] Jun 5 02:14:55 mail postfix/cleanup[22300]: 538BB9C1AD: message-id=<20120604181408.538BB9C1AD@mail.zimbra.local> Jun 5 02:14:55 mail postfix/qmgr[4464]: 538BB9C1AD: from=<admin@zimbra.local>, size=408, nrcpt=1 (queue active) Jun 5 02:15:05 mail postfix/cleanup[22300]: EDD0E9C1AE: message-id=<20120604181408.538BB9C1AD@mail.zimbra.local> Jun 5 02:15:05 mail postfix/smtp[22317]: 538BB9C1AD: to=<user@zimbra.local>, relay=127.0.0.1[127.0.0.1]:10024, delay=74, delays=65/0.02/1.6/7.8, dsn=2.0.0, status=sent (250 2.0.0 from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as EDD0E9C1AE) Jun 5 02:15:05 mail postfix/qmgr[4464]: 538BB9C1AD: removed
