With the proliferation of mobile devices, mobile learning has become a learning paradigm in education. The aim of this paper is to evaluate the media richness of various message delivery methods in mobile learning (m-learning) environment. This study evaluates media richness in respect to content timeliness, content richness, content accuracy and content adaptability in WhatsApp, Email, SMS, Twitter and BBM. One-way ANOVA analysis and Post hoc analysis show that: (i) SMS has better performance than WhatsApp, Email, Twitter and BBM on content timeliness; this implies that SMS may be more appropriate for delivering real-time information such as notifying or reminding of some time-sensitive matters, (ii) WhatsApp has better performance than Email, SMS, Twitter and BBM on content richness and so may be applied in information delivery that is rich in images and videos, (iii) WhatsApp has better performance than Email, SMS, Twitter and BBM on content accuracy and content adaptability. WhatsApp due to its media richness is more appropriate for supporting learning activities in a mobile learning environment. This study suggests that developers and designers of an m-learning environment could adopt WhatsApp as a suitable information delivery medium to support corresponding learning activities in a mobile learning environment.