A solicited letter is written when a former employer, professor or person you've had a business relationship is asked by you if they will write you a letter of reference sometime in the future. Normally if they assent to do so, you should assume they will write you a good letter which highlights all of your sterling qualities and glosses over any imperfections you may have. When you get the job interview and are told that you will be hired providing your references are good, you give the name and phone number or email address of the person(s) who agreed to write the letter and they are contacted by the prospective employer directly and the person who solicited the letter (i.e. the one who asked the employer if they'd write a letter sometime in the future), never sees it.
You write a solicited letter of inquiry when a business or agency advertises its products or services. For example, if a software manufacturer advertises some new package it has developed and you can't inspect it locally, write a solicited letter to that manufacturer asking specific questions. If you cannot find any information on a technical subject, an inquiry letter to a company involved in that subject may put you on the right track.
An unsolicited letter of reference is a letter of reference that tends to be seen as quite unbelievable. People arrive at a job with a letter in hand that they may have written themselves and it is such a glowing tribute to their work ethic and persistence in the face of insurmountable obstacles that you're unable to ascertain if you're not in the presence of the messiah.
There are disadvantages to the solicited letter. In a professor-student relationship, the professor and student have similar research interests (it was why the student did research with the professor in the first place). Unfortunately, no one wants to graduate a student whose career overshadows their own. As a result, it might take some time for someone who has gotten past the interview stage to determine that one of his/her reference letter writers is sabotaging their future prospects by writing uniformly nasty things about them or their abilities. Where 3 letters are required, it can require a lengthy process of elimination of first one reference, then another, and finally a 3rd. until it can be determined who is having a damaging effect on your future job or career prospects.
As a simple guideline, it is better to contact someone who is acquainted with your work who is not in direct competition for funding, grants and the like to write a solicited letter of reference than someone who will turn the exercise into a series of disappointing job refusals. The writer of the letter should attempt to insure the recipient that he will write a good letter, I've had situations arise when after going back to someone who said they'd write a good letter and I'd received a job refusal based on their letter alone, claimed they write "balanced" letters. This was the same professor who told his undergraduate students that getting a "B" in his course was like getting an "A" in someone else's course. A "B" on your transcript is still a "B". Nobody knows or cares about the personal standards of the grader except the grader themselves. Hence, be cautious.
Most companies will not accept an unsolicited letter of reference. Arriving for a job with one in hand is not your guarantee of much more than ridicule from a prospective employer.
Your letter of inquiry is unsolicited if the recipient has done nothing to prompt your inquiry. For example, if you read an article by an expert, you may have further questions or want more information. You seek help from these people in a slightly different form of inquiry letter.
GUIDELINES FOR WRITING THESE LETTERS:
- Early in the letter, identify the purpose — to obtain help or information (if it's a solicited letter, information about an advertised product, service, or program).
- In an unsolicited letter, identify who you are, what you are working on, and why you need the requested information, and how you found out about the individual. In an unsolicited letter, also identify the source that prompted your inquiry, for example, a magazine advertisement.
- In the letter, list questions or information needed in a clear, specific, and easy-to-read format. If you have quite a number of questions, consider making a questionnaire and including a stamped, self-addressed envelope.
- In an unsolicited letter, try to find some way to compensate the recipient for the trouble, for example, by offering to pay copying and mailing costs, to accept a collect call, to acknowledge the recipient in your report, or to send him or her a copy of your report. In a solicited letter, suggest that the recipient send brochures or catalogs.
- In closing an unsolicited letter, express gratitude for any help that the recipient can provide you, acknowledge the inconvenience of your request, but do not thank the recipient "in advance." In an unsolicited letter, tactfully suggest to the recipient will benefit by helping you (for example, through future purchases from the recipient's company).