I have a user who ignored any warnings about mailbox size, and was left
for some time being unable to send messages, at least to recipients
within our post office. It may be that her usual email client is the
native one on her phone (via GMS), since her question to me today was
prompted by seeing this message on her phone:

Failed to Add Item-

Mobility failed to add the following item because your GroupWise disk
space limit was exceeded.

So, now that some mailbox space has been regained, she'd like to know
how to find messages that she tried to send but which were not sent due
to that space restriction. Does anyone know? Would this be something
she'd have to do on her phone?