Duplicated email addresses

So BT announced they are leaving Yahoo!

I randomly logged in today to see if there was any communications regards this change. Truth be known I had kept it as an experiment to see what I continued to receive; and if any brands would stop communicating with me. I have no emails in the inbox with similar types of subject lines typically used for reactivation or COI emails.

Its been at least 2 years since it was my primary account and I can count on one hand the number of times I have logged into it. I will keep company names out of it, but to my surprise I noticed that there are several major brands that have been simultaneously email both old and new address.

This is not only subtracting from ROI but also affecting their email metrics. Can't say it enough, data is key!