First log onto ssh via putty.
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1. Install nano on your server
sudo yum install nano
2. After successfully installing nano type the following to get csf email related details.
grep -ni email /etc/csf/csf.conf
3. Now you have to note the query number which was generated from the above query, and search the line number by issueing this command.
nano -c /etc/csf/csf.conf
4. Go to line 1017 which says LF_EMAIL_ALERT = "1" and change it to
LF_EMAIL_ALERT = "0"
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5. Press the follwing to write into file
Ctrl + O
6. Exit by pressing the following.
Ctrl + X