Thanks to this Lifehacker post, I noticed Gmail is now letting users add email from other personal accounts.
That account has to support POP3, though, otherwise this won't work. I already tried with my corporate email account, and I was politely denied:
My company's mail server is Microsoft Exchange, and I'm not certain, but I don't think Exchange is configured for POP3 access. Damnit.
So I'm still stuck with the old approach, which is customizing my Gmail "From" addresses.
