The basic “truth in advertising” doctrine applies. An advertiser can certainly employ effective “teaser” copy within the subject line but not intentionally fraudulent information.
In addition, never use tactics intended to mislead the reader about the expected content. For example, do not use RE: or FW: in the subject to mislead the reader into believing this message is connected to a previous communication with another party.
Also, do not use subject line phrases intended to convey a previous friendship relationship when in fact none exists; for example “Hi”.
Conclusion – Falsified, misleading, and deceptive subject lines remain the hallmark of spam. Even the most novice Internet user can immediately recognize and delete Spam messages. Hence, legitimate email marketers should design their messages to appear as distinctly non-spam as possible.
The first step is a clear “From” address and header. The second is a credible subject line.
