Well, for starters, is sshd actually getting killed over an over again? Perhaps the server logs could tell more.
Second, abrt can be configured to go easy on the mails. I would recommend fixing the cause for this and only suppressing the notifications for as long as it takes.
I have installed quite a few updates, but the problem persists here too. My mailbox is flooded with thousands of e-mails every day, how do I disable e-mail reporting for the time being?
Yes, I can confirm that changing the SSH port stops flooding your inbox and makes your server even more secure, thanks to Martin Dias from the Plesk Online Community on Facebook for the heads-up.