To delete messages on an Android device, first you will need to open up the YouMail app and you will be navigated to your inbox. You can select the desired folder where you would like to delete messages via the drop down menu to the right of "Inbox".
Once you select the desired folder, press and hold on to the message you would like deleted. After long pressing the message, a check mark will appear to indicate it is selected, and you can then delete it by selecting the trash can on the top right-hand corner. You may select multiple messages to bulk delete.
You can also delete messages by swiping the message to the right.
Finally, you can also delete messages by opening the message you would like to delete and selecting the trash can folder in the upper right corner.