The 3rd form of "forward" is "forwarded."

You could mean a text, or an email. A forwarded text would show up as a regular text. A forwarded email would say forwarded.

Forwarded is the past participle of forward.

Most e-mails should NOT be forwarded, especially when it asks to be forwarded as part of a plan to gain wide distribution of the contents (which may include falsehoods or even malware).

E-mail is forwarded to advise someone of its contents, which may affect them or their work. It is also forwarded if it is sent to the wrong person or department by mistake.

Yes, "forwarded" is a grammatically correct word. It is the past tense of the verb "forward," which means to send something on to a further destination.