Thanks. What you said about that particular error message made sense. My husband suggested we change our cox account password to the old password because he felt that the problems happened after we changed passwords. I changed it on my mac and my phone but forgot his phone. I changed it on his phone and was able to receive. I waited 1.5 hours and tried to send a test and was successful. We didn't change any of the smtp settings on the phones.
I am hoping this is a fix instead of one of the sporadic times that it does send email. In the meantime, thank you so much for your help. I hope we have solved this. If not, I will talk to you soon.
P.S. I hope you get paid significantly more than tech support by phone as I feel like there's someone on the other end trying to help with more knowledge!!