Hello Harshraj Singh,
i had the same problem. I dealt with it by switching IMAP/POP in settings and create password application to skip 2FA.
This is the EmailConnector telling you that the values of the Email-server-setting are not correct. uid, password, url, etc. So can you show us what you have set (not the password of course)
Can you please confirm? Are you trying to test it on local?
If yes, please try to do it in a cloud environment?
If you cannot then, you can also try PaperCut, to test it on local and see if you receive any email.
I hope it helps.