Reading emails is slow

I get several emails listed , but it looks like it downloads them
when I click on them , taking maybe 30 sec in ver 8
in ver 7 the emails were already downloaded so I could
go thru the email very fast
how to fix this in ver 8 to be downloaded already for all emails

I noticed emClient email content loading to be only half as fast as my vintage WLM. With the latter content is practically immediately there, while in emC there is always a noticeable time lag.
Tried now -> account settings -> IMAP -> download messages for offline usage = on (was off).