You have mailed responses repeatedly to newspaper classified ads that match your qualifications perfectly. The ads don't mention the name of the company or person soliciting the resumes and you reply to a post office box, which provides no street address.

There's no way you can follow up to make sure the companies have received your information. Nevertheless, while you're not working with blinders on, you're still confident these employers will view you as ideal and call or e-mail you immediately. One week goes by, then two, and you don't hear a word. Since the employers are ignoring an obviously perfect candidate, you grow frustrated and angry at their rudeness and incompetence.

Eventually you decide recruiters in general have no empathy for job seekers. In fact, they seem to take perverse pleasure in playing mind games with anxious job hunters. It's almost enough to make you contemplate starting your own business!

If this has been your experience as a job hunter, you aren't alone. Most candidates who answer classified ads are similarly frustrated. You have a right to feel discounted. Be aware, though, that you probably haven't been snubbed on purpose. There are several reasons why corporate recruiters and search firms don't follow up on every resume they receive, even those from candidates who seem to be perfect matches. Here's why your resume may seem to have fallen in a black hole and you never hear from employers.

The first excuse is the high volume of work in human-resources departments. Like everyone else working in a lean, mean, stockholder-driven machine, human-resources professionals are stretched incredibly thin. Many do the work of two or three people. They can barely keep up with all the positions they're asked to fill, let alone respond to thousands of job seekers.

To them, you're just a two-dimensional piece of paper, a resume that may include appropriate key words. Unless your resume and cover letter position you as the answer to their recruiting prayers, your paperwork will be stored a computer database, a huge, generally ignored electronic file of candidates with potential. Your resume may also be discarded.

Human-resources pros don't like this impersonal system any more than you do. They like working with people, but they don't have time to contact everyone who sends them a resume.

Many resumes, especially unsolicited ones, are scanned directly into a computer system. If the company has an opening, the recruiter enters key words describing the job into retrieval software, which searches the database of candidates for a match. The process of having your resume emerge on top is tremendously complicated and filled with obstacles. To be selected, it must:

• feed into the scanner easily
• not include any italic or underlined words, which a scanner turns into gibberish
• be printed with sufficient white space to be readable
• contain the right key words
• include enough of the right key words to beat the competition

In other words, if your resume isn't eye candy for the computer, you're defeated before you start. With thousands of resumes going into this type of system at large companies, the retrieval software isn't any more likely to acknowledge you than a human.

A typical recruiter spends 10 to 20 seconds scanning the first page of each resume he receives. Unless he sees the skills and experience he's seeking, he'll pitch it. This means one-size-fits-all resumes and cover letters rarely make it through the screening process. If you aren't willing to tailor your qualifications to a particular employer's needs, you're unlikely to get a second glance.

Sometimes a company may advertise more than one position that fits your qualifications. But you mail one resume, assuming that you'll automatically be selected for the right position. This generally doesn't happen. If one screener rejects your resume, it's unlikely another recruiter will see it. If you're applying for three jobs, send three resumes.

To generate responses from employers who receive your resume, make it easy for them. Include a stamped, self-addressed post card with the following choices on the back:

This novel approach exhibits such an exquisite understanding of the recruiter's time constraints that he or she is likely to respond out of gratitude and admiration. In fact, this technique might earn you an interview, even if your qualifications aren't a perfect match for the job.

Some job hunters wonder why companies place "blind" ads which include only a box number for replies. Since the company won't reveal itself, they suspect that the job doesn't really exist. Here's why companies use blind ads:

• the human-resources department doesn't want to add phone calls from unqualified candidates to its already impossible workload.
• an executive search firm is soliciting potential candidates and screening responses before selecting finalists to present to its client company.
• a search firm or corporation is testing the water to survey available candidates for positions similar to the one described, making this a bogus ad.

If a newspaper or on-line career center owns the post office box, there's no way for you to determine the identity of the advertiser. Your only option is to tailor your resume and cover letter to the description in the ad and hope for a reply.

If the company uses a federal post office box, you may be able to determine the name of the advertising company by asking a postal employee to look it up for you. If you can learn the company's identity, you can identify and write to the human-resources director, who may award you points for perseverance and pass along your resume to the appropriate individual. By making this contact, you'll at least stand out positively from the crowd.

Most career counselors agree that job hunters shouldn't only respond to employment ads. Only a small percentage of current jobs are ever advertised. Even fewer are filled via newspaper or internet listings.

To maximize your job-search efforts, spend the majority of your time networking with friends, colleagues and other professionals. Networking is responsible for filling as many as 80% of all openings, so it's clearly a candidate's best choice of strategies for learning about positions and landing offers. It also gives you more control over your job search than responding to ads, sending unsolicited resumes or counting on an executive recruiter to recommend you for an opening. If you initiate and follow up on personal contacts, you'll cut your waiting and wondering time to a minimum.

If you want to respond to ads, only reply to those that list the name of an employer and contact person. Then research the organization and tailor the first paragraph of your cover letter to the company and your specific interest in it. Using an individual's name is a much better way to start your letter than, "To Whom It May Concern." You can also call or e-mail this person to inquire about the status of the opening instead of passively hoping to hear something.

In every situation, you have options. If the path you've chosen isn't working for you, try another. Life is too short to languish in job-search limbo.