'Content policy?

[LittleRob]

I've tried sending a confirmation email to a property auction company & get the message below:- 

Sorry your email could not be delivered due to content policy reasons. Please check your message content for URLs, content and subject matter that could be construed as Malware, Spam or Phishing before retrying. (6-1-3-1) ID (67D89E0801CFC17F)

How can the content of a simple 2 sentence  message be Malware, Spam or Phishing?

[gg30340]

Are you using the "reply to" function or is it a "new" email ? If you are using the "reply to" function it could be something that is in the original email that is causing the problem.