I use eM Client for a few weeks. I like it because it is an all-in-one application.
I do not have to enter my contacts in an e-mail program such as Thunderbird, which does not have enough fields for telephone numbers, e-mailaddresses and addresses.
And again in another program to get the other data fields.
So far I have used Outlook 2003 without caldav sync.
Now I use eM Client with CalDAV / CardDAV-Sync and it works very well.
Some things that I miss and would like to address these ideas as a feature request.
2 column view in the calendar. The left column 3 day, right column 4 days, per day a list of events with starttime. So you can see all events of the week in one view also on small screens.
2 columns wider than 7 columns so you can the more text. 2 events at the same time have enough space.
or Lotus Notes:
With some of my contacts it is necessary to communicate encrypted with PGP. With Outlook and pgp4win this was possible. Is it planned to implement in PGP encryption eM Client?
If you change from the calendar view to e-Mail view and back the current date is shown and not the last view. So you have to re-scroll again and again.
It would be better the calendar shows the last view.
I backup the database directory regular.
All local mail folders are stored in a file mail_data.dat. It must be saved each time the big mail_data.dat.
Better you could save individual mail folders in other files, like the .pst file in MS Outlook.
Now, only the changed files must be backuped.
greetings from cologne