The phrase "a modest letter" is correct and usable in written English.
It can be used to describe a letter that is humble in tone or content, perhaps lacking in grandiosity or excessive embellishment.
Example: "She wrote a modest letter to the editor, expressing her thoughts without seeking attention or praise."
Alternatives: "a humble letter" or "a simple letter".
He was most upset last month when a "modest letter" he wrote to fellow commissioners on the subject of national budget deficits was misread by outsiders as an invitation for governments to resume spending like drunken sailors.
John Grisham's site, somewhat more humble, is introduced as "A New Spin on Suspense," and includes a modest letter from the Doubleday author in which he says: "I'd like to welcome you to my Web site, something I know very little about.
(Charles Isherwood) 'GATES OF GOLD' Any good ham loves a deathbed scene, and Frank McGuinness has written a lovely one, and then stretched it out into a modest love letter to the theater (1 40).
Inside the room, a hidden projector illuminates a black wall with the names of the dead, one after another, each name materializing for a few seconds in modest letters and then vanishing: Prof. Dr. Furst Zu Bendnow... Maria Wolfgang Hetal... Achim Michson.
He wears thin white socks and brown shoes, black trousers, a white shirt with the company's name on it in modest letters.
The judge said she was considering whether to impose a sanction, which lawyers say could be a modest fine or a letter to disciplinary officials.
It is a handsome, fully annotated volume that adds about 300 letters to the 1,098 that were reproduced in the volume of letters edited by Rupert Hand-Davis and published in 1962, with a modest expansion to 1,262 letters in 1985.
For him, "lad" was probably the richest word in the language — a modest, slender triad of letters on which he hung his deepest feelings of fascination, lust, exclusion, and (especially when regarding soldiers in uniform) envy and gratitude.
"Anything I do, I always strive to do the best I can," he said, gesturing to his award letter with a modest shrug.
The relatively low cost method of sending a pre-warning letter had a modest impact on increasing response rates to a postal questionnaire sent to a group of patients for whom a low response rate was anticipated.
When they learned of her plan to use the letters in a modest memoir, they invoked the Steinbrenner family's copyright on them.
