Hi,
A couple of coworkers have large mailboxes with 3000 to 7000 mails. Hence it takes a while before the mailbox overview (first screen after logging in) is rendered. They thought Roundcube was hanging as Horde/IMP doesn't have that delay.
I presume the difference is because Horde/IMP is depending on the 'imap' PHP extension while Roundcube just talks IMAP over the established socket connection to the imap-server.
Can't Roundcube be configured to read the first 300 mails (or the first 4 pages) when logging in and read the other mails on demand, that is when the user uses the navigation in the top right.
In the majority of the cases one doesn't need to see the other/older mail. Or maybe the other mails can be read in the background after the 'homepage' is loaded. This allows reading the new mail etc and will make Roundcube more snappier.
Just my 2 cents.
Jasper