I have updated with iOS6.0.1 today (11/03/2012), after update, the mail deletion option is not showing on my iphone4. Any idea, how to delete my mails (gmail is configured on my phone).
For 'Delete' Option, you will have to switch 'Off' the 'Archive' option under Mail Settings.
Go to Settings > Mail, Contacts, Calendars > Mail > (Your Gmail Account) > Archive Messages > Off.
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