Both seems to be valid email addresses 
email@domain.web
  .email@domain.com
since any email address contains three components
<username>@<mail-server>.<mail-servertype or server-location>
Here android.util.Patterns.EMAIL_ADDRESS validates all the three components using regex and also checks if all three components are placed properly. Some common confusing examples are:
- com@web123.comis a valid mail address since- comcan be a user name and- web123can be a web server's name.
 
- .maths.apple@com.inis also a valid mail address since- .maths.applecan be a user name and- comcan be a web server's name.
 
Invalid case:
crick@.web.com is invalid since a . cannot come before or after @. No mailing system will be able to recognize the username or mail-server name.