Hi guys,

I’m having a fairly weird issue.

On my website I have a simple contact form. Name, email, subject, message.

The message should be sent to my domain name’s email (google apps hosted). The ‘from’ is the form’s email field.

However, depending what email address users have, the message isn’t arriving. I’ve noticed that people who send with a gmail address, get a ‘Undelivered Mail Returned to Sender’ message, reason policy rejection ‘SENDER_QUOTA_REJECTION’.

But, if the visitor fills out an hotmail address, then the email arrives as it should.

Any ideas? This really shouldn’t happen.

It seems to be solved when setting the visitor’s email as a reply-to instead of the ‘from’ and make the from a known email address.

Very strange though, so an explanation would be appreciated.

Don’t let the user enter the from-address - always use a from-address you know is allowed from the IP-address it is sent from, to avoid having your mail in the spam-folder, and other issues.

Also be careful with the data entered from the user: if you use it directly in the mail-header, a hacker can introduce a linefeed and use your mailform for his own spam. Best of all: never put it in the mail-header - second best: check that is does not contain a linefeed or carriage return.

Ok, but that does not really answer the question why it’s being rejected.

The input is sanitized & spam checked, so spam should not be an issue…