Web-based monitoring of SMTP email servers is usually performed using one of the two different approaches. The first uses a socket level connection to verify the target server is operational. The second, more comprehensive method is round-robin sending messages to your e-mail system and its subcomponents. Depending on your needs, hardware and company size both have validity and a rightful place. To determine what is best for your company, Let’s € ™ s examine in more detail both the advantages and disadvantages of each.
Socket connection is the most common method used by web-based monitoring companies because of its simplicity. A DNS check is normally performed, then a socket level connection to port 25 on your mail server is attempted. If DNS is ok and port 25 SMTP handshaking occurs, the server is considered operational. If not, then the proper notification methods activated. The socket connection method advantages are: speed, low bandwidth, and no agent or server changes needed. Because of its simplistic design, socket connection can be used to monitor SMTP servers your company does not own or manage monitor. The disadvantage of this approach is accuracy. Just because DNS is operational and handshaking occurs, this does not mean the server or subcomponents are actually processing the messages.
The second, less used, method is a round-robin process that actually sends test messages to your e-mail systems and wait for the message to be returned. As with the socket connection method, a DNS check is normally performed first. A test message is then sent by the monitoring company to your e-mail system. The message travels through your gateways, all subcomponents such as antivirus and content / spam filters, through the firewall to the appropriate internal server. The internal server, based on a predetermined server-based line, the message back to the monitoring company. If the message is received by the monitoring company within the set time, 15 or 30 minutes for example, the e-mail system and subcomponents considered operational. If not, then the proper notification methods activated.
If you use Microsoft Outlook and Exchange, a server-based rule would look like this: Apply this rule after the message arrives from EmailVerify@SiteRecon.com and “E-mail authentication” in the subject line, send it to “ webmaster @ reconstructive site. com
The advantage of this approach allows for the complete message processing for malfunctions. For example, a gateway controlled by the socket connection method can be fully operational, but a connected device spam filters or anti-virus process can be hung to stop message processing. Depending on the monitoring company, the possibility of a specific type of attachment to the round-robin-making process is also available. Including an attachment, such as for example the text pattern Eicar.Txt permits subcomponents such as antivirus extensive testing. The disadvantages to this approach are: increased processing from your servers as this test method, 96 messages per day with a 15 minute monitoring intervals, creating an email account to receive the test message, and the establishment of a server-based scheme.