Some messages about your problem on the Kayako community forums. Have you tried searching for them or contact Kayako support?
Chances are wrong, since "Kayako" and "support" are no longer a "thing".
They sold to a venture capitalist and virtually eliminated the downloaded version with absurd prices and total negligence.
With regard to piping, you can, as a temporary fix, switch to polling the email account via POP. If the pipe fails in Namecheap, it's on them, not the Kayako software. I know that on some vendors in the past, we had to include the pipe path in quotation marks while configuring it for it to work properly. I have never hosted anything with NC, so I'm not sure of theirs.