Can't Send Mail Out From My Home Account

Hello!

On my phone, I have 3 web-based mail clients which work fine. I also have my long running family account which is from our local internet provider. (wavecable.com) Well, I am able to receive wavecable emails but I can not send them out.

What I get is, "Unable to Send Email. A copy has been placed in your Outbox. The sender address (my wavecable account) was rejected by the server."

What server? And why is it rejecting my outgoing mail?

Yes, I can just take the wavecable email and send it out via my gmail or yahoo accounts but it is annoying. Besides which, the wife only has that same family address on her phone and so it's really inconvenient for her.

Thank you for any words of wisdom you can share.

Brian