How to Stop Spamming through Exchange Server
A high priority of network designers is to stop sending spam through their networks. Most of the email clients are configured to send mails using the SMTP protocol. Microsoft Exchange Server, though considered different from SMTP, also contains the latter as one of its many components. The MS Exchange Server is comparatively more effective than SMTP. Still, users who want to play around use the dependency of Exchange Server on SMTP to spam. How do they do this?
One of the main features of the Exchange Server is the Active Directory Service. This service stores the email address and other related information for users in a group or an organization. Based on the Directory Service, the mails sent by any user of the group or organization are placed into two categories.
If a mail is sent to a user whose name is listed in the Exchange Server, the mail is a normal one, also called an "internal" or "submit" email. On the other hand, if the mail is sent to users outside the group or organization, the mail is said to be "relayed", meaning the mail is relayed through different servers in order to deliver it to the intended recipient. SMTP relays are the most common method used for spamming.
As this mail carries the reference of MS Exchange Server in its header, it is hard for email service providers to tell if this email is regular mail or spam. This is where the spammers take advantage. One of the steps to avoid spam through SMTP relays is to turn it off. While turning off SMTP prevents users from sending spam using accounts dependant on SMTP alone, changes may be made to the Virtual SMTP Servers on Exchange Server to reduce the amount of outgoing spam.
Important Note: More and more network administrators are turning off the SMTP option on their LANs. This may cause problems in sending email in the future when most of the SMTP protocols across the world are turned off. Hence, it is better to configure your network’ email clients without POP (Post Office Protocol) or IMAP (Internet Message Access Protocol) options that use SMTP. Administrators can use other options such as HTTP (Hyper Text Transfer Protocol) so that they do not need to turn off SMTP on the LAN. Alternatively, set the LAN’s email client to use Exchange Server by configuring it to avoid users from misusing your network to spam.