Users appreciate this plugin for its ease of configuration and its effectiveness in ensuring emails from WordPress sites are properly sent using different email services like Gmail and Zoho. Many users found it simple to set up and noted that it resolved issues related to emails being marked as "from WordPress" or going into spam folders. The plugin is praised for its reliability and compatibility with various themes and other plugins. However, significant drawbacks include issues with updates that erase credentials without warning, leading to email service disruptions. Security concerns are also raised, particularly regarding storing credentials in plain text, which has been linked to data breaches like the Panama Papers incident. Users also experienced difficulties with Gmail authentication and lack of debug information when using certain mail services.