Mass update email addresses for leads/accts

[enricoproducts]

I have missing email addresses in excel for several hundred existing contacts. How do I update the contact information without creating duplicate contacts via the import process?

[Angel]

Is there a value on the Excel spreadsheet that you can use to match up the records in the Sugar database?

If so, then you should be able to leverage that and use the update feature within the Import options to update the records. Note that it may be necessary for you to create a custom index if the matching key in question is not something stored in a field that is already indexed by Sugar.