There are many synonyms for the phrase "cordial regards" that can be used to convey a friendly and respectful tone in written correspondence. Some alternatives include "warm regards," "sincere regards," "affectionate regards," "fond regards," and "regards with appreciation." Other variations on this sentiment might include "best wishes," "warmest wishes," or "kind regards." Ultimately, the choice of phrase will depend on the specific context of the communication, as well as the writer's personal style and relationship with the recipient. Regardless of the exact words chosen, however, the intent should always be to express genuine respect and goodwill.