Gmail no more with username and password

Pop is much better than Imap because you can combine all accounts into one global
You can use gmail with em only by imap because it is not identified by Google as a safe app
username and password is no longer accepted.

Google accounts no longer support username password logins, but do support oAuth. We made an announcement about that in March last year. You can find it here:

No thats not what I want. I want POP
Em creates always an IMAP Account.

You can no longer use POP3. Please see the blog link I gave above.

Ok then, I just look only directly on Google

I hope someday, you program that way, that 20 email accounts don’t have 20 inboxes, only one under local folders

With IMAP or Exchange your messages are stored on the server, not in eM Client. eM Client just shows you a cached versions of those server folders.

However, we do have unified Favorites folders in eM Client. That means you setup your 20 email accounts, and each has its own set of folders, but you can view all the Inboxes combined in one folder. The messages are still stored on each of the individual servers, but are displayed together in one folder in eM Client for your convenience.

20 times a set of folders and 20 times unused. No way

It would be the same whether you use POP3 or IMAP. There are still 20 server accounts.

If you want to view them all in one place, you can use eM Client, otherwise you will need to login to 20 separate webmail pages.