Smtp blocked

Help I have been working with Cox for a week and a half and still I can't not send emails from Outlook 2010 on windows or Microsoft 2013 Windows 8. I can received emails but not send here is the error message I receive Your out going SMTP email server has reported an internal error. The server responded :554 eastrmimpo 210 cox refused from 98.161.30. When I first received this cox told me I had too many devices connected and or a bad password. I disconnected all devices for one email but kept our most important email on one PC. I wasn't able to send via Cox webmail. I changed passwords. Waited 5 hours then 48 hours and was about to send Via Cox webmail but not Outlook 2010 or 2013 for either emails. I have talked with several techs level 1 and level 2 and they have checked and recheck my settings and I am okay. I have suggested to Cox that it seems that I am partially locked out. I asked for some facts from them of what is causing this and they are confused. One tech said it was Microsoft's fault, One said you must still have something connected or a bad password, okay tell me what or block it, they said they could not. Another one wanted me to delete everything from all my outbox on all devices, I wasn't happy but I did it. I asked for them to reset me, they can't. I asked for them to block all devices and then I can add one at a time or just one. I spoke with a manager and nothing. Funny thing is everything worked just fine until I was locked out and now I am broken and I am stuck receiving business related emails via cox and sending them via gmail, a very long week thanks to Cox and it is still going on. I have 3 email accounts 2 of them that are being used here in Omaha have this issue the other one is working just fine and he is out of state. Help please about ready to dump cox completely just to be done with this. I am wasting my time with this issue.