How do I set the mail type to POP instead of IMAP?

[crops]

Hello ,
my question my sound stupid but i didnt find anything relevant for this question.

So far when i setup my accounts on my Plesk Server all of them are IMAP accounts, but i have a client that wants to use a large number of mail accounts and i cant give him IMAP accounts since 100 mail accounts, if all mails are stored on the server would make his storage to 0, so i want to setup his mail as POP so nothing gets stored on the server for a long time and eveyrything is pushed to the client when a mailbox is queried. But there i cant anywhere to set the type of account to POP instead of the default IMAP... Could someone help me on this?

much appreciated