Open Source is currently being recognized by more organizations than ever before for its ability to give rise to flexible, cost-effective, and exceptionally secure software and technologies. Currently, over 75 percent of organizations worldwide are contributing to and consuming open-source software and products. The open-source community is expected to continue to grow and thrive in the coming years, which will further increase the overall credibility of Open Source and enhance the various benefits that open-source options are able to offer businesses and individuals alike. This article will explore why choosing an open-source email security solution can offer key advantages over proprietary alternatives including superior security, reliability, resiliency, flexibility, and cost-efficiency.