ZEMA in MN04

Dear All,

I have maintained ZEMA in MN04 for purchase order to be sent my email.

When i create PO, by default ZEMA is not appearing in messages screen.

But Printout(NEU) and fax(ZFAX) is appearing by default.I can able to select ZEMA from the F4 screen.

Is there any setting to be done to make ZEMA to appear by default?

Please advice.

Regards