Oh, let me rephrase that. I was meaning y'er in-game account. Emails don't deactivate, at least I don't think so.
Some FH accounts get deleted when a person no longer plays the game f'er a really long time. 'Tis to recycle and create more space, I believe. Y'er forum account may stay active throughout this process, but if ye been only gone f'er a year, I wouldn't be too concerned 'bout this topic. If ye were gone f'er 2+ years there would definitely be that possibility.