Confirmation Pop-up is Not Displayed When Sending an Email from a Case in Salesforce

To display a confirmation pop-up when sending an email from a Case, you need to switch to Salesforce Classic.

■ Email Sending Behavior in Salesforce Classic

If you are using Lightning Experience, click the user icon in the upper-right corner of the screen and then click [Switch to Salesforce Classic] to switch.

1. Click the [Cases] tab.

2. Click any case record.

3. Click [Send an Email] displayed in the [Activity History] related list.

4. Click [Send].

5. The "Are you sure?" pop-up will be displayed.

There is a feature request for displaying a confirmation pop-up in Lightning Experience.

Related Information: Pop-up and delayed transmission settings when sending mail -メール送信時のポップアップ、遅延送信設定