In early November, Porter Briggs interviewed six job seekers for a management position. Not a single candidate dashed off a thank-you note, but he wasn't taken aback by the lack of gratitude.

"People don't send them quite as much as they used to," said the founder and president of A Briggs Passport & Visa Expeditors in Georgetown. "I've already hired one of them."

While the custom of writing thank-you notes may be on the decline, the courtesy of sending them could make a difference between getting hired and getting crossed off a manager's list, career experts say.

Most employers expect to receive a thank-you letter after an interview, according to a survey of 650 hiring managers conducted in May. Nearly 15 percent of those surveyed said they would not hire a candidate who failed to send one.

Job seekers who don't send thank-you letters are missing an opportunity, according to Laura L. Viehmyer, chief human resources officer at the American Institute of Architects in the District.

"It is just one variable in the employer's overall analysis of a candidate's fit for the position," she said. "But from the candidate's perspective, why not add another plus in his or her column?"

Those who really want a job make it known, and one way of expressing interest is by writing that thank-you note. How swiftly and concisely they do it, experts contend, matters just as much.

"The first key to sending thank-you notes is to, you know, actually send them," said Bob Corlett, president of Staffing Advisors in Silver Spring. "Spell the names correctly and mail the notes right away. Most managers care if you sent one, not whether it was particularly good. Timing matters. The first note to arrive wins."

Thank-you notes should be sent the day after an interview "to demonstrate responsiveness and quick turnaround," said Yvonne S. Distenfeld, president of Lawyers On Call Inc. in Rockville.

Not everyone agrees on what form those thank-you notes should take. Distenfeld, who places attorneys and paralegals, said e-mail communication is commonly acceptable. And, the way Briggs sees it, time is of the essence, as the organization "may be making a decision imminently."

Others, however, favor a more traditional touch. "Handwritten is best -- unless you have handwriting like mine," Corlett said. "On personal stationery is second. E-mail is a distant third."

Not sure about which mode of transmission to employ? Try both. "There is a distinct advantage to the 'immediately and later' approach for the candidate," Viehmyer said.

"Using e-mail to send a thank-you note to each interviewer immediately after the interview conveys a message of appreciation, interest and technological savvy," she said. "Sending a handwritten note via snail mail a couple of days later confirms candidate interest and formally transfers the responsibility for the next communication to the employer."

A brief and businesslike note will work better than a lengthy and jovial letter. "One paragraph, consisting of four sentences, is perfectly adequate," said Stephanie Kay, co-president of TransitionWorks Inc., a Rockville consulting firm. If there's more, include a second paragraph.

"It's an opportunity to further sell yourself -- and to add something that you may wish you had said during the interview but forgot at the time," said Kay.

In composing the note, Distenfeld suggests avoiding the usual, trite openings such as "Thank you for taking the time to meet with me." Dare to be different by mentioning a point that came up during your conversation, she said. This shows the reader that you didn't just talk during the interview -- you listened.

When several people participate in the hiring process, don't forward the same missive to everyone. "Interviewers compare those thank-you notes and look for the candidate's ability to make a unique connection," Viehmyer said.

And don't bypass the middleman. If you send only one letter, said Julie Burritt, a human resources consultant at Nonprofit Staffing Solutions in Washington, it should go to the recruiter. "You would be surprised at how much say a recruiter has in who gets the job," she said.

Some managers may look at the thank-you notes they receive as "just one more thing to file," said Burritt, who admitted she does not place great importance on the thank-you letters she gets. However, she cautioned that other employers do.

"Everyone I have talked to who is in the generation before the Xers loves them," she said. "You will not lose a job opportunity for sending a thank-you -- unless it is addressed to the wrong company, or there are major spelling or grammatical errors. But you may lose the opportunity if you don't."