Form E-mails Not Getting Through

[Pier2Design]

This has become so serious it is threatening to end my business.

I have a site that has a registration form. That form sends three copies: One to the referrer, one to me, and one to someone else.

I get 100% of the registrations because I have a POP email account in the same domain. However the other two people do not get their copy. To complicate it, the one used to, then all of the sudden it stopped.

The form used to inject one of my e-mail accounts as the sender. This seemed the most reasonable since it was a message originating from the same domain/server. However when I changed the FROM to be from the person actually filling out the form, more registrations got through, but not 100% by any means.

I need 100% reliability. I cant have a POP account for every person because its a dynamic site/form and depending on the context it may copy to any of 50 people.

What can I do? I'm on a managed reseller plan.

[Matt]

There could be any number of reasons for this problem. At the end of the day it is a code problem though.

I suspect setting the from header to something that is not your domain would be the first mistake. Various spam filters are going to block that. You might use the Reply-To header if you want it to appear that it comes from the user's address if that address is on a different domain.

But it is impossible to say for sure without knowing exactly what you are doing. While we have a general idea, its not specific enough in your first post to what exactly it is you are trying to do.

[Pier2Design]

I changed it so the FROM is from an account with the domain, and I enabled DomainKeys. I've been playing with SPF too but it doesn't seem to make Gmail recipients happier.

The form comes through a plugin (Formit) in MODx CMS. I assume the script uses php sendmail because there are no SMTP settings.

Are there any more tools available for shared hosting to validate ourselves to the world?

[Matt]

It probably uses the php mail() function, which is a more common approach for php scripts that have a mail function but no SMTP function. php mail should work fine.

Do you get any bounce errors?