I claim the ornamental design for a fence post with rails, as shown and described.
FIG. l is a front perspective view of the fence post with rails;
FIG. 2 is a right-side view of the fence post with rails, the left side being a mirror image thereof;
FIG. 3 is a front view of the fence post with rails;
FIG. 4 is a rear view of fence post with rails;
FIG. 5 is a top view of the fence post with rails;
FIG. 6 is a bottom view of the fence post with rails;
FIG. 7 is a front perspective view of another embodiment of the fence post with rails; and,
FIG. 8 is an enlarged view of detail 8 of FIG. 1.
The drawings contain a symbolic break; the broken line showing within the symbolic break depict portions of the fence post with rails that form no part of the claimed design. The broken line circle of FIG. 1 depicts the limits of the enlarged view in FIG. 8. The other broken lines showing of items in the figures depict portion of the article and its environment that form no part of the claimed design.