BCC to Dropbox

BCC to Dropbox

I started using BCC to Dropbox and my email host returned a delayed message:

This is an automatically generated Delivery Status Notification

THIS IS A WARNING MESSAGE ONLY.

YOU DO NOT NEED TO RESEND YOUR MESSAGE.

Delivery to the following recipient has been delayed:






Obviously disconcerting given I rely on zoho--can somebody explain if this message will bounce or is the result of something specific?