Outlook & Hotmail

Outlook Mail that I send to Hotmail.com is rejected. Any ideas Thanks

Not enough information. Are the rejected messages to yourself or other folks? What error messages are you getting? Which version of Outlook [part of Microsoft Office]? Or is "Outlook" referring to Outlook.com [successor to Hotmail.com]? That's becoming quite a common issue thanks to Microsoft's propensity for confusing things by using the same name. Are you including attachments that may be too large for the recipient's ISP rules?

I mean sending from Outlook.com to Hotmail.com

I thought MS was going to eliminate all Hotmail.com.

error msg was Hotmail don't exist

I'm using both and don't have problems but then I don't usually send from one account to myself on the other. But I just did a test from my Hotmail.com to my Outlook.com [different addresses] and it worked as expected. I also sent a test from Outlook.com to Hotmail.com and it worked as expected. I did try sending from a local account but misspelled my address, naturally it failed, have to go out and will check later.

Microsoft does intend to end Hotmail.com sometime, maybe sooner rather than later but who really knows.