Return email?

I sent an enquiry email to a guesthouse in combodia, thru their website. At the bottome of the return email was this

Warning: this message was sent without Return-Path.
Ask the sender to correct Return-Path by adding '-f' to send mail script.
This is a sample php code:

mail (recipient,subject,message,'From: sender','-f sender');

I have an gmail account, is this common?

Thanks

It just means that the guest house has misconfigured their email server. Probably means you won't be able to reply to that email. Not a gmail issue.