I have found the fastest way to block multiple junk email address on a iOS 16 is to:
1) in the mail app tap the edit button in the top right corner
2) select the emails you want to block the sender, selected as many as you want (you just can’t press the “select all” for some reason step 3 will not work if you press select all) you have to select them individually.
3) press and hold on one of the emails you have selected
4) this will pop all the emails you selected into a group and then you will see a drop down that you can select “block sender” this will block the sender of all of the emails you have selected.
once you start blocking you will want to make sure you go into settings to check that blocked emails get moved to the trash.