Question about Outlook Express

I'm not sure if this issue is because I've messed something up with my computer/gmail/outlook/mail but I cannot get email to send via any application installed on my computer. 

I started with Windows 10 Mail... worked great for a while but then every time I sent an email out, I'd get this response:

"We weren't able to send this message, so we've put it in your Drafts folder. Before you try sending it again, you can check to see if the address is correct and that no attachments are too large." 

The address is correct, and most emails have no attachment.  

So, I tried Outlook- it wouldn't send emails either. It would download my entire inbox just fine, but when I tried to send anything I would get this error:

 0x800ccc0f

I followed every recommended fix guide online to no avail, so I tried and went back to Win 10 Mail, made sure it was up to date, and sent a few emails. First handful went through just fine, and then the same message as above started happening again.  

If anyone has any advice to fix this I would really appreciate. 

I'm a beginner artist who's just getting into 3d animation, but I mainly do 2d hand drawn frame by frame animation. I think it would be more engaging if there was a paint 3d animation maker for the creations we make on the other software. Something maybe similar to blender, but more simple without all the gadgets and confusing values that could crash a computer.

Perhaps something with the ability for making bones and tweening? I guess something like the original movie maker, but more advanced and upgraded? The same how Microsoft paint got the huge upgrade and advanced to 3d and 2d image maker.

Also I'm new to the discussion thing, I'm use to  the post thing.

I have not been able to log onto my Windows Live Mail Account  or Windows 10 Mail but can however access my email via BT Yahoo on Google Chrome. I have had  a couple of frustrated chats with BT. We have changed my password and BT Yahoo still works with the new password but I am still getting error messages on Windows Live Mail which is my preferred system as Ihave many folders and all my contacts on it.

I keep getting the following error message:-

Unable to send or receive messages for the Btopenworld------------ account. An incorrect password was entered. The next time you send or receive messages, you'll be asked to enter your username and password for this account.

Server Error: 0x800CCC90

Server Response: -ERR [SYS/TEMP] Server error - Please try again later.

Server: 'mail.btinternet.com'

Windows Live Mail Error ID: 0x800CCC92

Protocol: POP3

Port: 995

Secure(SSL): Yes

I had a similar problem back in December and firedog was able to help me. I have checked all the information on ports etc he told me then but they are correct. Can anyone help?

when  I am logged in to my live mail account and click the contacts icon the list of contacts does not appear.  Also the progress info at foot of screen showing 'authorising ' , 'checking emails' etc. is nor appearing.  How do I restore these details?

Derek