Unused, or previously used, email accounts are often spoofed (Faked) to create a ‘legitimate’ from address in spam emails. It is pointless complaining to your ISP and nobody else seems to care, so what can you do to prevent this happening? SPF DNS Entry. There is only one thing that can be done to hinder the ability of spammers to send mail with your domain name. You will need to request that your dns provider add an entry into your dns file called a SPF. This entry will specify the mail servers that are allowed to send mail with your domain name.
When other mail servers receive mail, they should check for a SPF entry, and if it exists check to see that the email came from that server. If it doesn’t then the other mail server will delete the message.
The problem is that the vast majority of mail servers do not do this check, so it will not stop the spammers, but any intelligent spammer will not choose to use a domain with a SPF entry, because it will reduce the amount of mail that gets delivered. Important Note: If you create an SPF file you can not send email from any other mail servers than those specified in the entry.
If you try to send email from a server that is not listed much of the mail it will not get delivered. For example, it is common for companies to send newsletters from third party providers. If they don’t find out the ip address of this provider and add it to the SPF file the emails will get blocked.
Remove any email dump accounts It is a common practice to have an entry in your email server like @yourdomain.com that tells the email server to accept any email address at your domain name.
I do not recommend doing this, because it means you will get any random email that someone uses to send you mail. Removing the dump account will not stop the spammers, but it will reduce the amount of junk mail you see in your inbox.