During an online chat, meeting, or other collaboration session among many participants, identification data items associated with a new participant are received and stored into a multi-field contact record in a local contact list. Storage of the new record triggers automatic extraction of a search key value for each data item of the contact record, including at least an email address value for the new participant. The extracted search key value is used to search a trusted administered contact information store for corresponding data items; and the contact record is automatically modified to include the corresponding data item from the trusted administered contact information data store.