From the 'Content Settings' section, you can choose to exclude details on old events in your Alert mails.
You can access these under 'Alerts' tab in the Dashboard under 'Content Settings' section
Select the option "Do not send updates about old events" and Click on "Save"
By using this feature, Old News, Funding Rounds, Soonicorn Activity, Acquisition Activity and Reports will not be displayed in your Alert mails.