Hi,

OK, thanks - it would be interesting to know exactly why this didn't work, and what precisely caused the mail delivery to fail, which we'll hopefully get clues about from your mail logs.

One thing I'm not 100% clear on is why you actually need a smart relay here. Ultimately, barring there being networking restrictions in place that prevent your host communicating over SMTP with the outside world, there's nothing a dedicated smart relay box can do that your own local Sendmail install can't. Unless as I say something is configured on your network to stop your own dev box sending mail to the Internet, then it shoud be perfectly capable of delivering e-mail via SMTP to any host without needing a relay.

Of course, other hosts may well still reject that mail for a variety of reasons (e.g. they think it resembles spam, your IP/network range has a poor reputation, your reverse DNS doesn't match your forward DNS, you've gotten yourself listed on an RBL like Spamhaus, etc, etc). So if that's the reason you need a smart host - your own dev box is being rejected by other Internet hosts - then you'd need a smart host on your network that had none of the problems of your dev box, which might actually be hard to do.

Do you have a corporate SMTP gateway or mail server that deals with the normal incoming and outgoing e-mail for your whole site ? If so, can you maybe configure your smart relay to be that host instead. I imagine that somewhere locally you already have a host that handles routine e-mail functionality, and it might well be capable of acting as a smart relay in that case (though it will probably need to be configured to allow the IP of your dev box to relay through it).