Can i sue or be sued if i have a clothing line without legal doucuments.

The owner of the clothing line, whether that be you individually or the llc, can sue for any copyright or trademark infringement.  You can have common law trademark rights, and remedies, even without registration, but you don't mention anything in your email which would be considered a trademark (unless you use the design as a mark designating your line, a la burberry).  While you can have common law copyright rights in any design which is sufficiently original, just by creating it, you can't sue for copyright infringement until you have registered that copyright.  Moreover, while you can register after the fact (i.e. don't register the copyright until you want to sue for infringement), your remedies will be significantly curtailed if you don't register the copyright within 3 months of its creation.  You do not need either a registered trademark or registered copyright to sell goods.