I understand that Pegasus mail is not loaded all inside memory.
But pleaase consider situation, when you have pegasus mail installed locally and you have remote mailbox.
I do not remember other application that silly exits with general protection fault during network unplug. May be that the crashing place might be located and there might be displayed some message box that asks user abort application/retry or something like this.
Every defined way how application finishes is much more better than GPF.
Without source code (and even with it) it is difficult to say more.
Anyway it is practically impossible to have network without faults. Somebody reconnects cables in a rack, somebody kicks to a cable etc .... First thing that I am noting is Pmail's GPF ..