Supported features question

Hi!

I’‘m currently making my last year project at a company and trying help them with creating a messagingservice for mobilephones. Though it would be nice if i could use a open standard for handeling all the lowlevel messagepassing, and XMPP looks like a good candidate. However i’'m not sure that all the features that we need is supported, maybe some more experienced users/developer could tell me if the following features could easely be implemented:

x Sending and receiving messages(500 characters). ( I think XMPP/Openfire support this)

x Messages should have a message-subject(30 characters). ( I think XMPP/Openfire support this)

x Time when message waas sent. (I think XMPP/Openfire support this)

x Last publishing time, after this the message will automaticaly be removed. (I unsure if XMPP/Openfire support this).

x Message should have a notation from who the message originated. ( I think XMPP/Openfire support this)

x Message should have a priorityflag, so client can display it with another color or show a flag that symbolize that this is a important message.

x The message should remain on the server until user choose to delete it or messagetime expire. So you could download and show a message several times in a row. (I unsure if XMPP/Openfire support this).

I think this is all… I know that some pieces could be implemented by extensions, but i’'m unsure about stuff like the last requiement.

Any answers would be more than welcome, and since i have not much time it would be nice if they came fast. =)

// Henrik