How does email threading/conversation work in different mail servers.

Email Threading Algorithm is the fundamental principle for Email conversation and threading. For this We have to follow the follwing algorithm. jwz algorithm/message threading.

Or we can follow

https://www.jwz.org/doc/threading.html

Reference of procedural language for the PostgreSQL database system.

 PL/pgSQL - SQL Procedural Language:
1. http://www.imada.sdu.dk/~jamik/db2-12/material/39-PL-pgSQL.pdf

or,
https://www.postgresql.org/docs/9.6/static/plpgsql.html

Kill port on windows and linux

On Windows:
step 1:Run command-line as an Administrator.
step 2: netstat -ano | findstr :yourPortNumber
step 3: taskkill /PID typeyourPIDhere /F

On Linux:
step 1: open terminal at root user
step 2: fuser -k portnumber/tcp

Deploy an application in production machine.

Steps for deploying an application developed in java in production machine.

My requirements for production machine.
Server Os :Cent OS
Application Database: Postgres with audit log
Application Server: Payera server
JDK: jdk 1.8

Steps:
1.  get ip server(live) and ping
2. ssh server_username@server_ip_address
    -enter password
    - then logged in to sever.
3. use vi or any other editor to create any config file in server (eg: config.properties)
    - press a for editing mode
    - press Esc for exist editing mode
    - press :wq for save edit content and exit
4. set up database
    - install postgres for centos.
          - BigSql Postgresql installation site reference and install
    - create tables, views and function through your database application
        - connect using eg: 192.168.1.111:5432
    - clear audit log of database.
5. setup Pstgresql archives if necessary
6. setup PgAuditlog and enable if necessary
7. to start/stop database after login into server
    - sudo systemctl start/stop postgresql96
8. install payera server from official link
9. install jdk from official link.
10. to start and stop server
    - sudo asadmin start/stop/restart -domain domain_name
    - to start as root and full permission
     -  sudo ./asadmin start/stop/restart -domain domain_name