We often meet with clients, network and friends. When the dialogue falls on work, then we often get asked the same few questions. Therefore we decided to write a short FAQ that answers these questions!
I hope you find it useful 🙂
People I don’t know say they are receiving SPAM mails from my email address
It is a well known problem through years.
It is properly not coming from you, but your email address can have been picked up somewhere public like a message board or hacked from a company where you have once registered.
There is little you can do and it will soon blow over again. Make sure that your have your Anti-virus installed and updated!
My customers and contacts are receiving SPAM from my email address
This is also a well known problem. This is a little worse, but it may not be your computer. One in your network of contacts may have had a virus that send them the whole contact list and now you are on it. For a while, you will properly see emails sent to or from you along with people you know. Make sure you have your Anti-Virus installed and updated
If you are in a company and you have network of computers and suspect that SPAM are being sent from in-house, please check the following below:
If you have double checked your own Anti-Spam product on your server and eliminated that possibility, please see the below tips that will properly solve your issue.
Configure your firewall
Ensure that only authorized users can send emails via your internal network. This is accomplished by creating a rule in your firewall to drop all outbound traffic on TCP port 25 (SMTP).
If you are hosting your mail server inside your internal network, ensure that you make an exception to the above rule to ensure that the mail server can still deliver on your behalf.
It is advisable to log dropped packets, so that you can identify any rogue computers on the network attempting to deliver mails directly.
Enable SMTP Authentication
Now that emails can only be delivered through your mail server, you must ensure that it will only rely emails on behalf of authenticated users.
Failure to do so will leave you exposed to abuse of the server, so it is important to get the configuration of the mail server right.
Protect your domain
Let everybody know who are trusted sender of emails for your domain. This can be accomplished using Sender Policy Framework (SPF):
You should create a SPF record stating that your mail server (and possibly any 3rd parties) are the only trusted senders for your domain.
On behalf of the SPAMfighter team
CMO – SPAMfighter.com