Performance Evaluation of IMAP and POP3 Protocols Using Optimized Network Engineering Tool (OPNET)




Ali, Shahbaz

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Abstract The volume of email traffic is growing rapidly over time. Recent years have seen an increase in not only personal and business email accounts, but also in the number of emails sent daily. According to the latest data, there was an approximately 6% annual increase in worldwide email accounts during the period of 2015 to 2019. In 2018, approximately 250 billion emails were sent daily worldwide and researchers are predicting this number to reach 347 billion emails daily in the next 5 years. These increases highlight the importance of email protocols. Email protocols have been evaluated extensively and various ways have been used to analyze their performance. In this project, two well-known email protocols, Post Office Protocol version 3 (POP3) and Internet Message Access Protocol (IMAP) are evaluated using Optimized Network Engineering Tool (OPNET). The performance of these protocols is evaluated for two different network scenarios with different link bandwidths, packet loss ratios, and packet latencies. The performance metrics are average TCP delay, average TCP load, average TCP retransmissions count, and average traffic received. The results obtained show that POP3 performs better than IMAP. The complex process of retrieving emails and synchronization which requires many TCP connections for IMAP results in a higher average TCP delay compared to POP3. POP3 also has higher average traffic received than IMAP. Further, the TCP load for IMAP and POP3 is similar.