External user email login issues

[Jeyganesh]

We have created the External users in our SharePoint Online using following gmail and custom domain emails:

1. xyz@gmail.com

2. xx@xyz.com

All these external user don't have office 365 account.

If we send the request it will ask to create Microsoft office 365 account or create the Microsoft public email account (ex: hotmail, live, outlook).

My Question is, they cannot access with Gmail or own domain email?

[#2]

Hi @Jeyganesh ,

If they don't have office 365 then they would need to create a Microsoft account. There is a setting to  enforce them to create an account with the email address you send the invite too. So they are logging in using their Gmail or domain name but using a separate password for the Microsoft Account. 

There is a 3rd option that allows them to login for 24hrs using a code which is coming soon (maybe here, I haven't checked recently). 

Hope that helps

Andy

[#3]

Pretty sure sometime ago they disabled Microsoft Accounts from having or being tied to custom domains. You now can only use federated accounts the default MIcrosoft accounts when setting up. You might be able to add an alias after the fact but I don't think so.