Our Exchange Server is Sending Spam Mails

Many times exchange Admin see this issue that Exchange server is sending spam mails. Which is not a good thing for an Exchange Server. Because it increases the chance of getting blacklisted.
In this article we are going to discuss about my exchange server is sending out spam emails continuously. 

How to know that your server is blacklisted

An exchange admin can identify this by identifying some different behaviors of exchange server. For Example: If there is a long list of Non Delivery Report Messages then you can assume that there is something wrong going on with your exchange server. You can also come to know by checking the sending Queue, where you will find a long list messages which have stuck in the queue.
After looking the above discussed behaviors of exchange server you must check that whether your exchange server is blacklisted or not. You can check it at www.debouncer.com website where you just need to enter IP address or Domain Name. There are many other sites too where you can check for blacklisted status.

Reason for Sending Spam Mails Automatically

The reason for sending spam mail automatically from your server is very simple that some other user or we can say any hacker who have entered into your server and accessing mailboxes and sending bulk mails simultaneously through a mailbox. The receiver of email have noticed these activities and submitted your IP address & domain name to blacklisted sites. There are many operators who manages their own database for blacklisted sites. Sometimes the issue may happen in reverse where Exchange Server or even Exchange Online misclassify Gmail as spam.

How to solve Exchange Server is Sending Spam Mails issue

If you find that your IP address or Domain Name is blacklisted then you should first find out why your exchange server is in blacklist. Whatever the issue might be.

Second action would be to clean the email queues and scan computer for any malware and viruses. Do a through check of all computers for virus in internal network. As it is possible that during email formation a virus may attach itself onto the mail. Which when detected by the recipients email security screen triggers a junk email alert. It can also be the cause automated multi send requests which get flagged as spam mails.
After performing prerequisites the main task free the Exchange Server IP address and domain name from blacklist. However, blacklists are maintained by different companies and operators. So you must figure out the procedure for removal of IP address from blacklist on a per operator basis.

Generally they maintain an online form which you have to fill and request for removal of exchange server’s IP Address and domain name from blacklist. But before submitting the removal request make sure that you have fixed the issues which had put the exchange server IP address into blacklist. Because if blacklist operator find the same issue again and again then they might block exchange server permanently.

Things to Save Exchange Server from Sending Spam Mails

There are following things which you can apply in exchange server and stop sending spam mails.

• Apply filtration for Outgoing & Incoming emails
• Install an antivirus in server as well as all internally connected machines

Conclusion

In this article we discussed about Exchange Server is Sending Spam Mails to outside networks and also discussed about getting off from a situation when an exchange server is blacklisted by operators. We also discussed about how we can prevent an exchange server from sending out spam mails and bulk emails continuously.

Frequently Asked Questions

• Q. Why does any Exchange Server start sending spam on its own?
  A: It is possible that your server is compromised and is being used as a rouge device by a hacker to send unsolicited emails in bulk.
• Q. What can I do if my Exchange Server is put in a blacklist/spam violator list?
  A: First gather the evidence was it you or your user behavior that caused this. If so there is no other alternative than to change the IP address. Otherwise you can clean queues, scan for possible malware, and don’t forget to request blacklist removal.
• Q. How to clean Exchange server email queues?
  A: Use Queue Viewer in Exchange Toolbox or PowerShell commands like Get-Queue and Remove-Message.
• Q. How to stop my Exchange server from sending spam?
  A: Implement email filters (inbound/outbound) and install antivirus on all network computers and the server.