Fastest IMAP4 email client for Android?

Heya! I'm looking for a IMAP4 email client for Android. So far I've tried the default that came with my Samsung S21 Ultra but it is really slow and doesn't synchronize all data (messages with attachments) but only seems to synchronize headers of the newest messages. Is it just how IMAP4 works or is there a better client that automatically downloads all messages and attachments so I can view them quickly? My web hosting is at https://www.xetnet.fi/ which has cPanel settings but I don't know if the settings on the email server have nothing to do with it?

One possibility is to use Gmail to download all the messages inside my Gmail account as a POP3 account but I hate to lose them from the server, which is why I prefer IMAP connection instead.