I guess I could have posted this on Rick's site. And in no way am I blaming the very ancient version of wwipstuff we are using because it still works.

Of course everyone wants to blame the FoxPro VFP9 West-Wind wwIpstuff.dll business when we get this 451 error.

451 451 4.7.0 Timeout waiting for client input (state 18).

It's a FoxPro job running in a scheduler software that is similar to the Windows Scheduler. It sends emails to our SMTP server and then it goes to the Exchange server and out the door.

The FoxPro email job works for 98 out of 100 other customers, but for the same 2 customers it fails every single time. And it takes 12 to 15 minutes to actually timeout. Because the job is on a ten minute timer schedule I had to split the FoxPro job up into two jobs - one for the successful emails and one for the ones that are going to fail.

Now, the painful workaround is to resend the email with attachment directly through Outlook. And that works 100% of the time.

I think the customer has some setting on their email server that is detecting that the email has been relayed or some other identifier.

Of course, this is a job for IT, but because it's a FoxPro program now I have to get involved.

Has anybody heard of this kind of problem?