SPAM or security issue? : Body of old emails being sent in new emails

My client’s website is hosted on hostgator.com. Today she started receiving emails but the body of the email was from a year ago.

Is this a security issue or spam issue and what is a suggested course of action?

Thanks!

Your question lacks context…I receive email all the time so? How is the email being received? How is the email being sent? What does the email contain? Etc., need context otherwise what are we suppose to say?