Can't write to imap.zoho.com any more?

Can't write to imap.zoho.com any more?

Hi,

I am used to leave a copy of sent messages in my inbox but this no longer works since yesterday. I can still access the imap server for reading messages but don't seem to be able to FCC (file carbon copy) messages into it.

Is this is a temporary issue or a feature that dropped?

Thanks