From the Southwest.
Mobile, June 6.
--This morning the steamer Daregan, in attempting to run the blockade, was captured.
She had an assorted cargo.
The operator at Jackson, on the 5th, reported, on the authority of Captain Evans, commanding scouts, that Marmaduke is blockading the Mississippi below and above Greenville with ten guns.
His force is large.
He has destroyed three transports, securing two cargoes, besides crippling three gunboats and other transports.
Among the latter the Marion and Fairchild, one gunboat, one transport and one hospital boat.
Four transports are between the batteries and cannot go up or down. 