Charter email not sending.

I posted a year or so ago, but tried a few recommended responses, but it appears to be getting worse. Anytime I leave my home or local community, but charter email will not send. I can receive but it will not send using Apple Mail. I am not called Charter support again all they do is blame Apple and then of course Apple will blame Charter. It's quite remarkable someone at either company has not figured this out win over 5 years. I see someone recommend turning off " automatically manage " on the apple mail site. I will see if that works. I have not converted all my mail to gmail, but it appears I will have too. Do people prefer gmail to iCloud mail?