you have new mail in/var/spool/mail/root prompt appears in Linux, and the solution to close the email prompt and clean up the content is

Reference article:

(1) You have new mail in/var/spool/mail/root prompt appears in Linux, and the solution to close the email prompt and clean up the content is given

（2） https://www.cnblogs.com/zdz8207/p/Linux-Centos-mail-root-sendmail.html

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