As someone who's designed and deployed plenty of email marketing campaigns, I have to feel for the poor sods who sent this electronic come-on to Washington Mutual customers today, as news broke that the Seattle-based bank's failure is the largest in our nation's history.Washington Mutual had $309.7 billion in assets, most of which are being taken over by JPMorgan Chase. The email carried an appeal for customers to save money — just the kind of capital that the company so desperately needed to stave off federal seizure and a firesale. Too little, too late after all those other email offers for credit cards and low, low introductory mortgage rates.