Gmail to Gmail, contact form won't work

I am having a problem with a PHP mail form on my website. There may be a simple fix but I don’t know it.

The form sends to a Gmail account and if the person filling out the form also has a gmail account the mail is never delivered, no I am not using the same account that is receiving the email ;). If a different email domain is used it seems to works fine.

What can I do to fix this?

What address is your mail form using as the sender? Make sure that your script is not trying to use the address that was entered as the sender — you are not GMail, so you should not be trying to send mail that claims to be from them.

a picture of the email header
Here is the header from the successful email. If the from/reply to address is any gmail address nothing comes through.

Is this wrong?

Yes, this is wrong. Your script should use an address associated with its domain in the From field. You can use the address that was entered in the form for Reply-To, but From needs to be accurate.

That seems to have done it. It even sent to my gmail address even though the reply address was the same address. I knew it would be a simple fix after all

Thanks a lot Andrew F