The term looks new? Nope, this is the reason why some of your mails go to Junk/SPAM section. You would have thought it was because of the words contained in your email address and message. But it might also be due to blacklisting. If the MX IP addresses of the mail hosting service is blacklisted then this happens. You have to check mail server blacklisting now and then to avoid such situations.
A mail exchanger record (MX record) is a type of resource record in the Domain Name System that specifies a mail server responsible for accepting email messages on behalf of a recipient’s domain, and a preference value used to prioritize mail delivery if multiple mail servers are available. (via Wikipedia)
You can use a Tool called MX ToolBox for this. This tool will list MX records for a domain in priority order.
The MX lookup is done directly against the domain’s authoritative name server, so changes to MX Records should show up instantly. You can click Diagnostics, which will connect to the mail server, verify reverse DNS records, perform a simple Open Relay check and measure response time performance. You may also check each MX record (IP Address) against 147 DNS based blacklists. (Commonly called RBLs, DNSBLs)
Check Mail Server Blacklisting – What You Should Do?
1. To check the mail server blacklisting, you need to find MX IP addresses of the mail hosting service, whether they are blacklisted or not.
2. Check whether the mail server supports open SMTP relay.
3. Use password for outgoing SMTP messages from the mail server.
4. Ask Support whether they use multiple outgoing mail servers and whether they swap out IPs from time to time.
Like SPAM sites hosted in shared server affects other sites, if other people using the same server misuses the Email IP address then it will also affect you, because it uses the same email server i.e., the same IP address.
If you are using Google Apps for your email and stuffs then it won’t be an issue for you since Google handles it and it won’t use your Mail Server.