The .txt file extension suggests someone has dumped a list of email addresses. A file named -20-869---orange.fr--wanadoo.fr--sfr.fr-.txt likely contains harvested addresses.
If you are working with a list of French ISP leads, follow these golden rules: -20-869---orange.fr--wanadoo.fr--sfr.fr-.txt
If you are a cybersecurity researcher or developer who found this file: -20-869---orange.fr--wanadoo.fr--sfr.fr-.txt
The Forgotten Risk of Legacy French ISP Email Addresses (Wanadoo, Orange, SFR) -20-869---orange.fr--wanadoo.fr--sfr.fr-.txt
Files formatted like this are typically used in two contrasting industries: