for the Verizon webmail, the Classic style, you can set type of message one the general preferences page , in the options.

[General Preferences [ Back to Mail Options ]
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Name and Email
From name: This name will appear on the From line of outgoing mail.
Reply to: (if different from your Yahoo! address, e.g., name@company.com)
Folders/Search Results
Message Ordering: (default)
Descending by date (new messages appear at top)
Ascending by date (new messages appear at bottom)
Messages/results per page: Show messages/results on each page.
Special Folders:
Save your sent messages in the Sent Items folder
Redirect incoming unsolicited mail to the Bulk Mail folder
Composing E-mails
Mode:
Compose messages as color and graphics
Compose messages as plain text]
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If your using the Yahoo mail version- it doesn't have all the options available yet.