Is it possible to ensure that we do not end up entering duplicate data in the Contacts? Like can we check if certain fields like email address or phone number cannot be duplicated while entering new data. It will mean checking the fields while saving new data.
We don't check the data you upload for duplication since it's a custom database (everybody's fields are different) and we don't want to determine for people what constitutes a duplicate. What you can do is sort on a field like email address and remove duplicates on the frontend quite easily after an import. We might consider building in an interface for selecting fields for entries to ignore on import but that gets pretty hairy with custom databases so we'd really need to think it through.