Hey Abdulhadikh,
Thanks for the feedback! Let me try address each of your points.
1: Add the ability to change the notifications sound
We’ve got a new set of sounds being worked on, but they’ll be ready closer to launch 
2:Add the ability to change folders & labels name and color that already available! And add color wheel to choose any color ! And if you can retrieve the labels colors !
Renaming labels in the app is on the way, but in the meantime if you edit them on the web they’ll get synced across. You can change the colour of a label by long pressing it in the list and tapping “Label Color”.
3:Add the ability to choose default alias for each folder!
So I understand correctly: if you reply to a message inside a certain mailbox/smartbox it defaults to a particular alias? Neat idea, we’ll look into it!
4:I do have catch-all enable i would like to see the app organizes emails based on the alias that received the mail !
If you have an example of this, I’d be interested to hear more!
5:The ability to send from xxx@subdomain.domain.com like the one available on fastmail app and website
You can setup an alias like that now. When you’re in the compose window, tap “From” and then tap “Add Alias”, then type the address you want. You’ll need to make sure it’s approved with your mail provider first though.
I can’t setup startmail mail !
Is this a specific mail provider? If so pop me a DM and we can troubleshoot.
And I don’t get notifications for all mail I received !
Again pop me a DM with the email you’re having the problem with and I can take a look for you.
Thanks!