Friends Kingdom: [iPad] Email Questions

Not sure if I've asked this before.

Every few months my email app decides it cannot receive emails, and to get round this I create a new account using one of my alternative blueyonder email addresses. I have three, but when everything is working properly regardless of which email address my mail is sent to, it will arrive in my 'inbox' regardless of which account is receiving mail. When I've created the new account it automatically duplicates all the folders and emails except for the 'sent' folder which does not inherit any emails. This I understand. In the past I've then deleted the original account which was playing up, then created it to download the folders and messages. I can't remember what happened last time I had to go thru this rigmarole, and I don't want to lose the emails in my 'sent' folder especially as some are concerning the death of my mother.

If I was to create a new account with my 2nd email addy, delete the original account then create it again, would it be 100% guaranteed to download the emails in the 'sent' folder?

Also can't remember if I asked this or not. What with my iPad being silly and Virgin having emails problems I'm getting very frustrated.....

My slower trusty laptop uses Windows Live Mail 2011, incoming mail is POP3, and outgoing SMTP. I see on my iPad Mail program incoming is IMAP and outgoing SMTP. What's the difference?

I see in the iPad settings I can create an account for Outlook.com, is that the equivalent of what's on my iPad? Is there another email program I could download which would automatically import all my emails including those in my 'sent' folder?

Apologies for the long-winded questions, but my brain is fed up and tired.

Janet.