Slow to load messages

This has been mentioned previously, but I can’t find anything that helps me.
I have recently converted from Thunderbird and quite like the feel of eM Client. However it seems to take forever to download messages. I know it has been mentioned to go to the IMAP tab in the Accounts area and tick download for offline use. I have done this for my Gmail account and it may have helped a bit, but I get very few emails on this address. My other account, the primary one, does not have an IMAP tab, only POP3 and SMTP. What do I do? This aspect of this client is killing my enjoyment. I don’t understand why the developers haven’t made the immediate download an option, or have they?

POP3 downloads the full message and it’s attachments to the computer immediately on sync. The sync interval can be whatever you want it to be from 1 minute to years. You can change that in Menu > Tools > Settings > General > Synchronization.

There are some things that can influence the speed of the download like incorrect POP3 settings, large attachments or a slow Internet connection.