what is the use of pmd tool in java
PMD (software) PMD is an open source static Java source code analyzer that reports on issue found within application code. PMD includes built-in rule sets and supports the ability to write custom rules. PMD does not report compilation errors, as it only can process well-formed source files. Issues reported by PMD are rather inefficient code, or bad programming habits, which can reduce the performance and maintainability of the program if they accumulate.
Simple Mail Transfer Protocol Email is submitted by a mail client (mail user agent, MUA) to a mail server (mail submission agent, MSA) using SMTP on TCP port 587. Most mailbox providers still allow submission on traditional port 25. The MSA delivers the mail to its mail transfer agent (mail transfer agent, MTA). Often, these two agents are instances of the same software launched with different options on the same machine. Local processing can be done either on a single machine, or split among multiple machines; mail agent processes on one machine can share files, but if processing is on multiple machines, they transfer messages between each other using SMTP, where each machine is configured to use the next machine as a smart host. Each process is an MTA (an SMTP server) in its own right.