exim -bpc

To check the email ID, sender and receiver of the each email:

exim -bp | more

To delete frozen emails from the mail queue, execute:

exim -bp | grep ‘frozen’ | awk ‘{print $3}’ | xargs exim -Mrm

similarly, to delete emails sent using a script’

exim -bp | grep ‘<>’ | awk ‘{print $3}’ | xargs exim -Mrm

Answer: Exim is a mail transfer agent (MTA) used on Unix-like operating systems. It aims to be a general and flexible mailer with extensive facilities for checking incoming e-mail.

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
Dallas Marlow, suggested following clean command:
# exim -bp | exiqgrep -i | xargs exim -Mrm

Further readings:

• man pages awk, exim
• Exim documentation