A letter of support for a person seeking to immigrate into the United States should be mailed to the embassy or state department where the person is applying, according to Sample Letters World. The letter should briefly introduce the author of the letter and his or her relationship to the applicant, then describe the applicant's character in positive terms, adding a specific detail or anecdote if possible.
If the letter is written to verify employment, it should cite the applicant's name and the name of the company where he or she will be employed, states Immihelp. The author should be a principal of the firm. The letter must include an offer of employment, the specific duties of the position, any educational or training requirements, the date of anticipated employment and the wage or salary to be paid, according to Imminfo. The letter should also mention whether the employment offer is contingent on approval from the immigration service.
In the closing paragraph, the letter should thank the reader and provide contact details so the immigration service can reach the author if more information is needed. The letter should be notarized, according to Golden Gate Immigration, especially if it references a personal relationship such as marriage that may affect the immigration process.