For the social and organizational parts of your brain, iPhone makes available Mail, Contacts, and Calendar apps; the settings for these apps are covered in the following table. You access the settings listed here by tapping the Settings app icon on the Home screen and then tapping Mail, Contacts, Calendars.

Setting Description
iCloud Choose to sync mail, contacts, calendars, reminders, bookmarks, notes, photos, and documents and data from an e-mail account wirelessly using iCloud. Set up the Find My iPhone service.
Add Account Add and manage e-mail accounts.
Fetch New Data Turn on/off the feature that pushes new e-mails and contacts and calendar info for Microsoft Exchange and iCloud accounts to you automatically.
Show Set how many recent messages to show in Mail.
Preview Set how many lines in e-mail messages are to show in the Inbox preview.
Show To/Cc Label Turn display of the To/Cc label on or off in e-mails.
Ask Before Deleting Turn on to display a confirmation dialog before deleting e-mails.
Load Remote Images Control whether images on websites that are referenced I emails are displayed in the emails; displaying such images can allow a site to gather some information about you and your iPhone.
Organize by Thread Turn on a feature to organize replies to e-mail messages to and from anyone so those messages appear together in a sub-folder.
Always Bcc Myself Turn on to send a copy of every e-mail to yourself. (This is in addition to saving a copy in the Sent folder.)
Increase Quote Level Add one level of indentation to text when you reply to a message.
Signature Change the signature at the end of all your messages. (Sent from my iPhone is the default message.)
Sort Order Specify the sort order for contacts (first/last or last/first names).
Display Order Specify the display order for contacts (first/last or last/first).
My Info Access a list of contacts to choose one to base your info on.
Default Account Specify which account is to be used by apps when working with Contacts.
Import SIM Contacts Imports contacts saved to your phone’s SIM card to the Contacts app.
New Invitation Alerts Turn on alerts when you get a new invitation in Mail.
Time Zone Support Turn on time zone support to show event data and times in your time zone; set your time zone.
Sync Control how far back in time events are synced when you perform a sync with iTunes via a calbe or Wi-Fi.
Default Alert Times Set up the default time increment for alerts (such as on the day, 1 day before, and so on) before a birthday, event, or all-day event.
Default Calendar Choose whether to use the built-in Calendar program or a calendar from a synced program such as Gmail or AOL.
Shared Calendar Alerts Turn on to have iPhone notify you when events shared between two or more calendars are modified or deleted.
Default List Specifies where reminders that you create outside of a particular list will be saved.