Email marketing, known for its high return on investment, is increasingly being leveraged by companies, but the complexity of email testing presents unique challenges that surpass traditional browser testing. Email testing tools have emerged as essential resources to address these challenges by ensuring emails render correctly across various clients, optimizing deliverability, and supporting A/B testing for content effectiveness. Notable tools in 2022 include testRigor, with its AI-driven platform that simplifies testing through plain English instructions and comprehensive functionality checks, and Litmus, which allows teams to preview and test emails across over 100 providers and devices while offering spam score assessments. Email on Acid provides pre-send issue detection for links, accessibility, and content verification, whereas Preview My Email focuses on deliverability and performance, featuring a drag-and-drop editor and blacklist checks. Each tool offers specialized capabilities to enhance the effectiveness and reliability of email marketing campaigns.