- Go to https://www.linkedin.com/psettings/member-data and ask for a fast download of your connections
- Unzip the file and look for files called Connections.csv and Contacts.csv, then upload them to your http://group-mail.com and proceed to merge them
- If the total number of connections and contacts is small, check them up one by one using https://rapportive.com/
Otherwise, blast them all using email blind copy or http://group-mail.com/ to blast them all: Proceed to process the bounces and invalid emails.
Then audit with https://rapportive.com/ what is left, one by one, and take decision weather or not to maintain or keep the connection. Otherwise, delete connection, and pass the email to a Deleted Pool