You can have up to five different email addresses to represent distinct functions or departments for each store or view. In addition to the following predefined email identities, there are three custom identities that you can set up according to your needs.
Each identity and its associated email address can be associated with specific automated email messages and appear as a sender of email messages that are sent from your store.
Changing Store Email Addresses is one of the most important tasks when you start selling on Magento 2. To change your store email address you can do the following steps
Before you can configure email addresses for the store, each must be set up as a valid email address for your domain. Follow the instructions from your server administrator or email hosting provider to create each email address that is needed.
Stores. Then under
Store Email Addresses.
General Contactsection, and do the following:
In the Sender Email field, type the associated email address.
Repeat this process for each store email addresses that you plan to use.
If you use custom email addresses, make sure that you update the configuration of any related email messages, so the correct identity appears as the sender.
Sales Emails. The page has a separate section for each of the following:
Ref: Magento 2 user guide
It comes to the end of tutorial: How to Change Store Email Addresses in Magento 2.