I checked out free fruux.com sync service with eM Client. Its nearly great.
Setting dav.fruux.com as account gets it all: contacts, tasks, calendar. As easy as setting up a Google account.
Found 2 bugs.
BUG IN CONTACTS: As soon as I add a photo to a contact eM Client fails to upload this contact and displays “Internal Server Error“. (@~2012-06-04 08:05 MEST)).
If I add the contact photo on another device, eM Client receives and displays it correctly but fails to upload the contact again after a change.
Removing the photo on eM Client fixes this and the upload works again.
Calendar and tasks sync works quite well.
BUG IN REMINDERS: iOS-reminders with location based reminder will sync as textual location information via fruux.com to eM Client reminders, but the location text misses separating spaces between street, town and country because iOS syncs the sepratators as a line feed. E.g. a reminder setup on iOS with a reminding location based on a contact address
will appear in eM Client as task with location
„Porsche-Platz 123456 FoobarDeutschland“.
Copying the location from the synced eM Client task via clipboard to notepad shows that there are still line feed characters in the location string.
Not clearly an eM Client issue but something to work out with fruux.