This guide will help you to change max blocked count that applies within CSF configuration.
First, login to WHM panel by using root login.
Now search for CSF plugin menu.
Scroll down a bit and find csf - ConfigServer Firewall.
Click Firewall Configuration.
Make sure testing mode is turned off.
Scroll down and find LF_FTPD.
Change the number 10 to anything else you wish. This LF_FTPD applies for maximum wrong password attempt from FTP account before got blocked.
Scroll down and find LF_SMTPAUTH.
Change the number 50 to anything else you wish. This LF_SMTPAUTH applies for maximum wrong password attempt from mail SMTP transactions before got blocked.
Scroll down and find LF_POP3D
Change the number 50 to anything else you wish. This LF_POP3D applies for maximum wrong password attempt for POP3 protocols before got blocked by server.
Scroll down and find LF_IMAPD
Change the number 50 to anything else you wish. This LF_IMAPD applies for maximum wrong password attempt for IMAP protocols before got blocked by server.
After that scroll down into the end by click Change to submit the changes.