I currently have different POP-email accounts.
I would like to have some sort of Exchange environment, in such a way that on all my devices (computer, phone etc) the same email is displayed (and not "a copy on the server").
Is there a tool to 'convert' a POP-email account to an Exchange one? If so, which one?
In this way I can have (hosted) Exchange for my mail?
... and how do I copy those?
Like a setting "Check mail from other accounts (using POP3)" as in GMail?
Is it also possible to import an Outlook pst-file in this environment, so that I have all my mail present?
Google Apps for Business, You can set it to monitor external POP accounts, with option to not leave copy on the server, you can import a PST, you can access the master Google Apps mail account using Gmail.com/POP/IMAP/ActiveSync(iOS/WP7/Win8)/Outlook Sync connector/Native Android app/iOS App.
For Free and a good weekend project (If you don't have experience) -
Do you have a spare PC? if so, you can install linux on it (Any one you want), and then install Webmin (Makes it easier), or at least Fetchmail on it. Set an account up with whatever you name, point it to send the email to that account, then turn on the mail server up - from there - connect your email program with an account that would be something like this:
email@example.com (whatever your IP would be) Password
But - this will only set up the incoming, then you have to set up for sending, but Google works great for that.
If you don't have a spare PC and don't want to get one used then of course use a Virtualbox or whatever you want on your computer and have it do that too. Or if you prefer just go and buy a service from a provider.