Related question: I use many different email addresses in Outlook 2013. I've been able to correct the new relay problem for actual email accounts from non-Cox addresses by sending through the servers for those accounts, but I'm having trouble with a couple of forwarding addresses. For example, one organization has an address for me (let's call it me@place.org) that forwards to one of my other addresses. When doing business for that org, I receive email at that address; until recently I had been able to send email from that address using Outlook 2013.
I've been getting a combination of the usual relay error message and also "The following recipient(s) cannot be reached:" sometimes with no recipients in the list.
Is it possible to continue to use that email address in the from field while sending from my home computer and my Cox ISP?