the built-in full-text search will find text in a rich text field, but I doubt it will find it inside an attachment (plain text). Is it possible that search will find text inside an attachment? any idea?
Subject: Can search find text inside an attachment (plain text)?
Yes, if attachments are indexed (check the options for full-text indexing).
Subject: Can search find text inside an attachment (plain text)?
if attachments are included in the full text index (see options for full text index in the database properties) then Notes will find text in all attachments that Notes can view (plain text, Word documents, Excel sheets, …)