You will find this setting at Dashboard -> Support -> Email Notifications -> General Settings. Below are settings available:

From Name

It is senders name shown in email notification a recipient will get. It can be your company name, website name, your personal name, etc.

From Email

It is email address from which your emails will be sent from. We highly recommend having setup SMTP plugin to deliver emails correctly for authentication so that mails will not go in spam or junk folder.

Reply to

It is optional setting which when set, email replies from recipients will come to this email address. If not set, email reply will be sent to From Email set above.

Ignore Emails

Many times you might not want to send email notification to some email addresses. You can add those email addresses one per line in this setting.