Now checking it against my database of known compromised or unsafe domains.. you'll see another reply if it's in there. If not, it's likely safe to open.
For more information about risks involved in shortened URLs, read this article by Forbes.
This auto-reply (on posts) is throttled 1/10 to reduce spam but if it still bothers you reply "OFF FURL" (I'll still check previews against my database). In alternative reply REVIEW for manual review and whitelisting.