Thaw one 10-ounce package frozen red raspberries; reserve 2 tablespoons berries for garnish.
Drain remaining berries, reserving 1/2 cup syrup.
Dissolve one 7/8 ounce package low-calorie raspberry-flavored gelatin (2 envelopes) in 1 1/4 cups boiling water.
Stir in reserved 1/2 cup syrup, 1 tablespoon lemon juice, and dash salt.
Chill till mixture is partially set.
Add 2/3 cup evaporated skim milk, chilled icy cold; beat at high speed with electric mixer till soft peaks form, about 4 minutes.
Fold in drained berries.
Pour into 6 1/2 cup mold.
Chill till firm, 2 to 3 hours.
Unmold; drizzle with reserved berries.