You read this article probably, because you have tried to send an email via smtp server smtp.forpsi.com and such error has displayed
550 5.1.0 cNkj1y0022zrrQM01NkjaD policy violation, see https://support.forpsi.com/kb/a4067
The error was caused with emails sent from your public IP address, that were marked as spam with our email system. From safety reason, smtp access of your public IP address to smtp.forpsi.com was temporarily disabled (access via POP3, IMAP and webmail still works).
Spams didn't have to be sent from your email account. Somebody, who uses the same public IP address as you, could send the spams.
The blocking of your email account will expire no later than in 24 hours.