On your last sentence, this happens when you try to fix it by using the accountpane. go to account settings, scroll down left side to 'outgoing server (SMTP) and change the Description field for each one, such as entering the email address for that server. Then, go to the account pane for each account and verify that each has the right SMTP server.

its now saying that I may have exceeded the maximum number of connections to this server...

I've tried that and am just going in circles - I change one and it still changes both.

Can you do a screenshot of the Outgoing server (SMTP) pane that shows all SMTP servers? And also do a screenshot of the account pane (the one that shows SMTP link) for each account?

I think this is what you want David. Your patience is much appreciated

No, I want the account pane, not the server settings pane. It's the one just above 'server settings' It shows the SMTP link on bottom line

Is this right?

On the SMTP server settings, you have user name as 'brian' - it must be the full email address. Othewise, you will not connect.

Okay, did that. Still refusing to send emails from either account

Look at the bottom line in each, and you will see you have both of them pointed to the same SMTP server. the hotmail account should be using the other SMTP server. You never posted a screenshot of the SMTP server for hotmail, but it would be the one that just as outlook.com in description field.

it's smtp.office365.com, not smtp.365office.com

If I have now done this right, still wont send

These are 3 screenshots of the hotmail account. Whilst I know nothing, it does strike me that the third looks wrong.

You are still using smtp.365office.com instead of smtp.office365.com. also, the SMTP setting for hotmail needs to have the hotmail email adddress, not the outlook one. Your goal in this is to have the email address for incoming be the same as the email address for outgoing.

So corrected office365. Now it is stalled again - see screenshot

I have no idea what is happening here. It's no lie to say I'm almost in tears over this. I need to walk away for a while My feelings are not a reflection of your considerable efforts but my inability to cope with this problem and its resolution

Look at the text. It says you are sending as the outlook account for the hotmail account. You changed the 365office error, but did not change the email address on the SMTP setup for hotmail. Your last screenshot had the outlook email account there. See attached:

As I said earlier, if I alter the hotmail address (as you indicate) it also alters the outlook address and vice versa. Now I'm getting messages that it is sent but cant be saved in the sent folder and then another message saying its all timed out

See attached

It keeps telling me to reduce the cache settings on the server so have reduced from 5 to 3. Still no change