Old version of Microsoft Outlook does not work with Office 365 with MFA enabled, which will faill at sign in stage.
This Guide walk you through with proper configuration to make it work even for old vero of Outlook.
1 Logon to https://www.office.com
2 Open this link: https://portal.office.com/account/ (Or go to My account)
3 Click on Security & privacy -> Additional security verification -> Create and menagae app passwords
4 Create an App password, give it a proper name, copy the password save it for later use.
5 Open the Control Panel.
6 Type mail in search bar, click on search result
7 Click Email Accounts…
8 Click New…
9 Select Manual setup or additional server types, then click Next.
10 Select Microsoft Exchange Server or compatible service, then click Next.
11 Enter the following in the corresponding fields:
User Name: username
When finished, click More Settings …
*Warning: Do not click the Check Name button at this step, or the configuration process will fail.
12 Click Security
13 Uncheck Encrypt data between Microsoft Outlook and Microsoft Exchange.
Choose Anonymous Authentication from the Logon network security drop-down menu.
14 In the Connection tab, check Connect to Microsoft Exchange using HTTP, then click Exchange Proxy Settings…
15 In the Use this URL to connect to my proxy server for Exchange field, enter outlook.office365.com.
16 Check the Only connect to proxy servers that have this principal name on their certificate, then enter msstd:outlook.com in the associated text field.
17 Make following changes:
Check the On fast networks, connect using HTTP first then connect using TCP/IP box.
Select Basic Authentication from the Use this authentication when connecting to my proxy server for Exchange drop-down menu.
18 Click OK.
19 Click OK.
20 Click Check Name.
21 An authentication prompt will appear. Enter your [email protected] and password form step 4 in the corresponding fields, then click OK.
22 Click Next >.
23 Click Finish. Your account will be setup and you can open Outlook to begin using your Exchange account.