My wife and I have recently installed Windows 10 and on both our computers E mails (Outlook) will not  send and remain in the Outbox.

We have dragged existing messages to draft and try again with another test message  but nothing works

Any suggestions?

As a test you could simply create a new account on the windows 10 box (or in outlook). By entering all the information from scratch to see if it`s something that did not follow during the migration. 

In outlook can you go in the account parameter and make sure all the info are OK.

I strongly suggest just recreating them if need be.