There are a bunch of public email addresses that have worked.
savenow2@sprintemi.com
savings@sprint.com
savings@sprintemi.com
sero@sprintemi.com
They come and go. I've always been able to get past the portal site using one of the above.
And you can always just do a search on google for "@sprint.com" or "@sprintpcs.com" or something. Steal somebody's name, but that's not so cool... I can't condone that, lol.