Quick access. Search related threads. Remove From My Forums. Asked by:. Archived Forums. Sign in to vote. Hello, I am using exchange for a school project I know everyone says why not ? Thanks J. Thursday, April 15, PM. Then join the second machine to the domain and then install Exchange.
By adding another DC to the existing domain I'm not sure what you are getting out of it? You need a domain to install Exchange. Friday, April 16, PM. Ok thats what I thought. For instructions, see Configure junk email settings on Exchange Online mailboxes. If the unwanted messages are newsletters from a reputable and recognizable source, unsubscribing from the email is another option to stop the user from receiving the messages.
When multiple users are affected, the scope is wider, so the next best option is blocked sender lists or blocked domain lists in anti-spam policies. Messages from senders on the lists are marked as High confidence spam , and the action that you've configured for the High confidence spam filter verdict is taken on the message. For more information, see Configure anti-spam policies.
If you need to block messages that are sent to specific users or across the entire organization, you can use mail flow rules.
Mail flow rules are more flexible than block sender lists or blocked sender domain lists because they can also look for keywords or other properties in the unwanted messages. Regardless of the conditions or exceptions that you use to identify the messages, you configure the action to set the spam confidence level SCL of the message to 9, which marks the message a High confidence spam.
For more information, see Use mail flow rules to set the SCL in messages. It's easy to create rules that are overly aggressive, so it's important that you identify only the messages you want to block using very specific criteria.
Also, be sure to enable auditing on the rule and test the results of the rule to ensure everything works as expected. When it's not possible to use one of the other options to block a sender, only then should you use the IP Block List in the connection filter policy. For more information, see Configure the connection filter policy. It's important to keep the number of blocked IPs to a minimum, so blocking entire IP address ranges is not recommended.
You should especially avoid adding IP address ranges that belong to consumer services for example, outlook. Spam filtering by using blacklist providers is a good brick in your wall against spam in your company. But it is only one brick and does not build a wall. That means in addition you should consider implementing Anti-Spam software that queries the whole email and checks specific words or phrases in it.
But be careful, Spam filtering means that a small percentage of email that may be lost if your spam filtering software is not configured properly. So prepare yourself with a good plan and check your configuration in a test lab before bringing it on your live servers. If your plans and test labs are working properly, do not hesitate to implement Spam filtering within your email organization. It will minimize the time of your users dealing with spam emails every day. And this will lead to a higher productivity range in your company.
Spam filtering by using blacklists with Exchange Server is a quick, easy and cheap way to reduce spam emails in your company and may be a first step for proactive messaging systems even for small and medium sized companies. Spam filtering software requires an investment and therefore is primarily used in bigger companies. I've been working for about 20 year in IT with a focus on Microsoft technologies, specifically the cloud.
I work on Azure at a huge German Service Provider and have also implemented it as an architect with smaller customers.
Your first tcpdump shows the TCP session information for what is presumably an SMTP communication session but gives you no information regarding that SMTP session and is therefore almost worthless in troubleshooting your problem. Your second tcpdump doesn't show any SMTP connection that I could find and is therefore worthless in troubleshooting your problem.
Restrict all outbound communication TO port 25 for all internal hosts except your Exchange server. None of these are guaranteed to keep you off of the blacklists, but they're helpful in that regard. This is invaluable in troubleshooting SMTP problems. Not a lot to go on here, but CBL will only list you because you have infrastructure which has been used by spam senders.
That might mean you are sending out spam, but it might also mean that you have an open proxy HTTP, Socks or other or you may have a vulnerable html form on a website you are hosting. CBL should give some idea as to why you were listed.
If your machines are sending out spam then you should probably have a default deny-all policy on your firewall, closely monitor both allowed and denied traffic and only open ports when you are sure nothing is attempting to send out on those machines.
You should also take a look at what ports you have open externally to make sure nobody is using any form of proxies, and you should make sure any websites you are hosting are secure.
You've mentioned you run McAffee on all of your machines. Are the virus definitions kept up to date? If you have some suggestion as to particular machines behaving badly then you might want to run another vendor's antivirus on them to see if McAffee missed anything.
It took a few days but we believe we have finally resolved the problem. It turns out that when our firewall was replaced the new configuration was sending out reports outside of our network and then back in, instead of just internally.
So several days of trouble shooting was the result of just one misconfigured email going out at midnight each night. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more.
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