There are several settings that can be adjusted to customize the texting experience on your iPhone. Preferences such as group texting, message previews and MMS are all adjustable through Settings.
From the iPhone home screen, tap Settings.
From the Settings screen, scroll down and select Messages.
Here you will see several options with On/Off sliders.
The first, Show Preview will decide whether the message portion of a text will appear on your home screen when received.
The Repeat Alert option will cause a sound notification to ring twice, if ignored, after the initial message is received. MMS messaging needs to be in the On position in order to receive photos and videos through a text message. To text multiple recipients at once, turn Group Messaging On.
If you will be using a group messaging application from the App Store, the Group Messaging preferences will need to be turned off in order to work correctly.
The Show Subject Field option will create a subject line in all text messages, much like that of an email.
When Character Count is on, the characters you have left (maximum 160) will be displayed next to the message.