How to opt-in to email and out of email communication:
Login to https://scoutbook.scouting.org/ it may redirect you to https://scoutbook.scouting.org/mobile/
Click on My Dashboard > My Account > Email > Opt In
NOTE it is highly recommended that you Opt In. If you Opt out, you will not receive any email from scouting.org and Pack 905 uses its calendar to send email reminders about events, so you may find yourself out of the loop on a lot of activities.