Know what I hate? When you spend half an hour writing out a cover letter, aching over every sentence trying to sound eloquent, professional, enthusiastic, and otherwise a man worth hiring. You get everything as close to perfect as you can possibly think it is, read it over three times to make sure there are no spelling or grammar mistakes, and even double and triple check to make sure you actually attached your resume to the e-mail. Everything's perfect. It looks great. It's the best damn cover letter you've written yet, so you hit "submit."
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Only to realize you forgot to fill out the "Subject" field. My mood is ruined.
I agree with Lil, but to be honest, even after sending the email again, the odds that your getting the job or not hung on such patently honest mistake are slim. They either dig you enough to make you an offer, or there's a more preferable candidate. (Notwithstanding serial and consistent misspellings, grammatical errors, or unprofessional tone, which I don't think omitting a subject header qualifies.) That said, I totally know the feeling you have. I hate it, too. It always takes hitting the send button for you to magically spot what was wrong with it.
Well, let me ask you this. Normally I'd call in a day or so to follow up on a resume submittal if it's a job I'm super enthusiastic on. This one I am particularly interested in. It just so happens that they happen to be damn near within walking distance of where I live. I know that people aren't supposed to blindly walk in to businesses and drop off unsolicited resumes. Do you think it'd be a good impression to walk in to follow up and drop off a physical resume?
I wouldn't want to recommend anything in particular. Employers are all different. But if you decide to walk in, you could say: 1) I was wondering if you received the resume I sent a couple of days ago. Could you check? 2) Do you know when HR will be making a decision? 3) I might be leaving town over the holidays and I would really like to find out more about the job before I leave. Can I meet HR briefly now? 4) I sent in my resume by email as the ad suggested, but I'd also like to drop off this letter of recommendation. It's stapled to the back of this hard copy of my resume. 5) Please give HR this xmas card and bribe. (ummm, just kidding).