If you would like to send a message to your provider from your Android device, please review the following:
Once you have signed into your account, please locate the Menu button on the top left side of the screen (see image below).
Next, select "Messages".
You will then need to select the "Compose" button in the bottom right corner.
On the next screen, please be sure to select the provider [A] and input both a subject [B] and body [C] of your message, and you should be able to send the message successfully by tapping the "Send" icon in the top right corner (shown below).
You should receive a pop-up confirmation message that your message was sent successfully. Messages sent successfully may be referenced in the "Sent" folder, found in the "All Folders" section of the "Messages" category.