When I sync with Nokia Suite, how can I make sure that none of my contacts and calendar items are accidentally deleted?

You can ask Nokia Suite to warn you when 5 or more items are going to be deleted during syncing.

To modify the options, do the following:

  1. In Nokia Suite, go to Tools > Options and select Contacts. Under the option Deleting in sync, choose whether you want to receive this warning before deletion.
  2. Then, select Calendar and tasks, and choose if you want to receive a similar warning for these items as well.