Searching for electronic mail (email) messages with attachments at a wireless communication device

1. A method comprising:

receiving a set of email messages at a wireless communication device, each of said email messages having at least one chunk of an attachment of the email message provided to the wireless communication device in response to user-initiated requests from the wireless communication device;

for each email message of said set received at the wireless communication device, maintaining an indicator of whether at least one chunk of said attachment of the email message has been displayed on a display or played on a speaker at said wireless communication device;

identifying a subset of said set of email messages on the basis of said indicator for the attachment of each email message of said set received at the wireless communication device and at least one user-specified parameter, wherein each of the at least one user-specified parameter can be set to a value so that email messages having an attachment for which at least one chunk has been displayed on a display or played on a speaker at the wireless communication device are identified based on said indicator for the attachment of each email message of said set received at the wireless communication device;

wherein for each email message of said set received at the wireless communication device, the presence of at least one chunk of the attachment of the email message within an attachment cache serves as said indicator for the attachment; and

displaying a representation of said identified subset of email messages at said wireless communication device.

2. The method of claim 1 , further comprising displaying a user interface at said wireless communication device for specifying said at least one user-specified parameter.

3. The method of claim 1 , wherein each email message identified at said identifying has at least one attachment having content that is displayable or playable at said wireless communication device.

4. The method of claim 3 , further comprising instantiating an object-oriented class which implements a first object-oriented interface to represent each attachment whose content is displayable or playable at said wireless communication device.

5. The method of claim 4 , further comprising instantiating an object-oriented class which implements a second object-oriented interface to represent each attachment whose content is not displayable or playable at said wireless communication device.

6. The method of claim 5 , wherein said first object-oriented interface and said second object-oriented interface are both defined using the Java programming language.

7. A non-transitory machine-readable storage medium storing code for execution at a wireless communication device for implementing acts of a method, the method comprising:

receiving a set of email messages at said wireless communication device, each of said email messages having at least one chunk of an attachment of the email message provided to said wireless communication device in response to user-initiated requests from said wireless communication device;

for each email message of said set received at the wireless communication device, maintaining an indicator of whether at least one chunk of said attachment of the email message has been displayed on a display or played on a speaker at said wireless communication device;

identifying a subset of said set of email messages on the basis of said indicator for the attachment of each email message of said set received at the wireless communication device and at least one user-specified parameter, wherein each of the at least one user-specified parameter can be set to a value so that email messages having an attachment for which at least one chunk has been displayed on a display or played on a speaker at the wireless communication device are identified based on said indicator for the attachment of each email message of said set received at the wireless communication device;

wherein for each email message of said set received at the wireless communication device, the presence of at least one chunk of the attachment of the email message within an attachment cache serves as said indicator for the attachment; and

displaying a representation of said identified subset of email messages at said wireless communication device.

8. A wireless communication device comprising a processor and a memory, the processor configured to perform acts of a method comprising:

receiving a set of email messages at a wireless communication device, each of said email messages having at least one chunk of an attachment of the email message provided to the wireless communication device in response to user-initiated requests from the wireless communication device;

for each email message of said set received at the wireless communication device, maintaining an indicator of whether at least one chunk of said attachment of the email message has been displayed on a display or played on a speaker at said wireless communication device;

identifying a subset of said set of email messages on the basis of said indicator for the attachment of each email message of said set received at the wireless communication device and at least one user-specified parameter, wherein each of the at least one user-specified parameter can be set to a value so that email messages having an attachment for which at least one chunk has been displayed on a display or played on a speaker at the wireless communication device are identified based on said indicator for the attachment of each email message of said set received at the wireless communication device;

wherein for each email message of said set received at the wireless communication device, the presence of at least one chunk of the attachment of the email message within an attachment cache serves as said indicator for the attachment; and

displaying a representation of said identified subset of email messages at said wireless communication device.