Another 3 SQL Server features NOT supported by Azure SQL databases

1. Attach a database or backup command
   Nope – You can use automated backups instead of the backup command.
2. Common Language Runtime (CLR)
   Nope.
3. Database mail
   Nope.

This list was taken from Azure SQL Database features 9/22/2017.
Watch for updates as features are added or replaced with alternatives.