SharePoint Online List - Row Limit for Lookup

[izzatdarani]

Is there any row limit for a lookup column to lookup to? If yes, what is the threshold number?

For example, List A wants to set its field Country Lookup by looking up field Country from List B where Email from List A = Email from List B. List B has 10k rows.

Below is the error message receive in List A.

Appreciate your help. Thanks

[#2]

@izzatdarani Historically (using Classic experience) the threshold for lookup of elements in a list has been 5.000 and as far as i know this has not changed.

Are both of your lists "Modern"?

Best regards, Magnus 

[#3]

It's just what Magnus said...to mitigate the problem, try to create indexes in the lists you are linking with the lookup column

[#4]

@MagnusGoksoyrOLDProfile yes I'm using modern experience

[#5]

I'd like to understand on how these indexes will help. Will it help if I set up the field "Email" as the index?