Most network administrators are aware of how to check to see if your mail server is on a blacklist whether it be a RBL or DNSBL or any of its variations. The problem with most of them is that most of them check by IP Address. What about your domain reputation.
There are a number of sites that you can use to check your domain reputation to see if your email is or should be flowing properly. Following is a list that I use to check a domain for its reputation in regards to sending email effectively.
Before you whitelist a domain in Spam and Virus filter you should always check to determine the reputation of a domain. Additionally, you probably should not whitelist a domain that gives out free email accounts such as gmail.com , yahoo.com, hotmail.com etc. If you need to white list a sender from one of those domains you should whitelist only the user e.g. firstname.lastname@example.org , email@example.com , otherwise you may be opening up the floodgates of spam coming to your server.
Ron has been a network administrator since the 1994 and has worked extensively with Microsoft, LINUX and FreeBSD products. He has also owned and operated a successful ISP business and has consulted to many companies offering network security services and management.
Whether you have a network in your home or business, you need to make sure that it is secure and can be accessed remotely. It is essential that you have a complete look at your network from both internally and externally. We are all about Network Security!