Question: What is Exim Mail Server?
Answer: Exim is an open source mail transfer agent (MTA), which is a program responsible for receiving, routing, and delivering e-mail messages (this type of program is sometimes referred to as an Internet mailer, or a mail server program).
Question: What is Exim Mail Queue?
Answer: Manage the Exim mail queue via SSH. … The MTA (Mail Transfer Agent) that runs on your server is called Exim and it controls your email deliveries
Question: Can I remove Mail Queue all by Shell or SSH?
Answer: Yes You Can. Exim is a Mail server, It’s controlled by Linux Command. So you can Use those command given down to remove the Mails from the queue.
To print a list of the messages in the queue, enter:
# exim -bp
To remove a message from the queue, enter:
# exim -Mrm {message-id}
To remove all messages from the queue, enter:
# exim -bp | awk '/^ *[0-9]+[mhd]/{print "exim -Mrm " $3}' | bash
By Those, You can Able to delete all the Mail queue from the server.
For More Information Please Visit: https://www.exim.org/