M110419-Testing EMAIL


Testing an email server before it is deployed is critical to ensuring continuous email flow. This article present the methodology required. This process is fairly simple and can be performed from any computer on every email server. Email servers use Simple Mail Transfer Protocol (SMTP) to transfer mail. SMTP has long and historically been part of the public Internet since it first officially came to life in August of 1982 with the publication of RFC821. RFC821 is based on the earlier work described in RFC772 (MAIL TRANSFER PROTOCOL).

To use this server testing method you will need a computer with network reachability to the mail server. The computer will need to be able to use the TELNET protocol.

Follow the steps below to test the email server. For most of these steps a server response of '250 OK' means the command was successful.
NOTE: This has been formatted for you to copy and paste to a notepad like application where you can substitute the [content] and then paste the entire test at once.

telnet [server-name] 25

HELO [your domain name]

MAIL FROM: [test Email Address]

RCPT TO: [recipient address]
DATA
Subject: [time] [server-name]

this is a test
.


======

NOTE: end the data portion of the email test with a single dot '.' and then issue the command QUIT to terminate the server connection.

By changing the MAIL FROM: and the RCPT TO: addresses you can also ensure that the server is not an open relay.



Originally published APR, 2011



Articles
Networking

N090307-Duplex Mismatch
N090905-Multi_IP
N090825-Clear_ARP
N20110904-Mask_table
N091010-ASA_WCCP_LINUX
N20110930-MRTG
Servers

W090905-DHCP-Options
L091028-Crontab
L100519 Linux Files 1
S121220-xymon_cc
Misc.

M110419-Testing EMAIL
M20110818 - Malware Education

eSubnet Fragment

Receive insights into networking, security
and IT management from our newsletter