I received an email "Marketo Support Awaiting Customer Input Reminder " this morning.
I thought it is strange, because I am waiting now.
I checked my case via marketo.com support page.
My comment was not there.
So I posted my comment again via marketo.com support page.
No error was happen, but my comment was not added again.
Finallyt, I tried to post 4 comment that is divided original my comment.
It's OK.
My comment is too long (almost 4K char) for this system???
ButI think that no message is not useful for users.