Incoming Email + SharePoint Online

Option 1: Site Mailboxes

This option allows for setting up an Exchange mailbox used to collaborate between team members.  Emails can be sent to the mailbox to be shared among team members.

Advantages

• Allows end users to create these mailboxes from the SharePoint online ‘Add an app’ page.
• Permissions set on the SharePoint site are also applied to the mailbox.

Disadvantages

• Only one mailbox can be created per site.
• Mail and documents do not live in SharePoint. Data is accessed through Outlook Web Access.
• Site Mailbox is chosen for you based on the SharePoint site name.
• Cannot set up event receivers or workflows on the data.
• Documents and emails are opened in outlook web access, and not SharePoint

Option 2: Office 365 Groups

Uses the Office 365 group functionality to set up a shared work space for collaboration.

Advantages

• A collaboration space is created to share documents, calendars, conversations.
• Feature is integrated with your OneDrive for Business site.

Disadvantages

• Every group creates a new hidden site collection.
• No workflow options.

Option 3: Azure Logic Apps

Azure Logic Apps can be used to set up connectors between an Office 365 mailbox and a SharePoint list.

Advantages

• Processes email within a mailbox to the associated SharePoint list.

Disadvantages

• Must have an Azure subscription.
• Must pay licensing fee for Logic Apps.
• Requires setting up a new user and mailbox for each list (requires user to be licensed for Exchange Online and SharePoint Online).

Option 4: Microsoft Flow

Microsoft Flow is a feature offered in Office 365 to allow processing email messages in Office 365 to SharePoint libraries.

Advantages

• Can process email attachments from an Office 365 mailbox into SharePoint.
• Can configure to use one mailbox to process to many different lists.

Disadvantages

• Requires setting up a user to go with a mailbox in Office 365 (requires user to be licensed for Exchange Online and SharePoint Online).
• Only has template for email attachment. No current offering to save the email itself.
• Additional cost per user for Microsoft Flow Licensing.

Other More Option:- 

https://www.peters.com/email-enabled-lists-office-365-sharepoint-online/