By default, when your org enables Approvals in Chatter, you are notified about approval requests by both email and a Chatter post. To stop receiving the posts in Chatter, opt out. If you do opt out, the posts don’t appear in your feed but they do appear in the associated record’s feed.
|Available in: both Salesforce Classic and Lightning Experience|
|Available in: Enterprise, Performance, Unlimited, and Developer Editions|
|To view an approval request post for a record:||“Read” on the record|
From your personal settings, enter My Feeds in the Quick Find box, then select My Feeds.
Deselect the option to receive approval requests as posts.
Save your changes.