weirdness with mail function

PHPrincess

I have some form processing code that displays different messages depending on the result of the call to the mail() function (it checks for true or false). As far as I know, this used to work fine. But now it's doing something strange. The email is getting sent, but the mail() function isn't returning a result, neither true nor false. I have no idea why this is happening.

I am not getting any warnings. I've tried it with and without the 4th parameter, additional headers, specified. I've tried it with various formats of "From" field in the additonal header information. It works normally on my own computer (returning true or false)- this is only happening on our server, and as far as I know, it only started doing this recently. We didn't find anything weird in the logs. We did upgrade to a newer version of PHP4 a few months ago, but we didn't notice this issue then.

Does anyone know (or have guesses) as to what would cause the mail() function to not return a result (despite the fact that the email is indeed getting sent)?

devinemke

what do see in the output from [man]var_dump[/man] with the return value from [man]mail[/man]? be advised that [man]mail[/man] will return true only if the mail was successfully sent to your SMTP app. this does not necessarily that the mail was sent or not. did you perhaps makes changes to your server's SMTP config?

PHPrincess

var_dump returns 'bool(false)'. And the email is still getting sent through. I know that the result of the mail function does not necessarily relate to whether the email was actually sent, however, in the past this did work on our server- it did return true; the SMTP server was seemingly communicating correctly with PHP.

Apparently, the SMTP configurations have not been modified since last year. The only thing that has changed this calendar year is the version of PHP4 we are using: we went from 4.3.7(? not 100% sure it was .7, but certainly 4.3.x) to 4.4.2 a few months ago. This in and of itself shouldn't have caused a change in the return value of the mail() function, unless something weird happened somewhere in some settings that could cause such a change, or if something just got corrupted. I just have no idea where to look or what settings to check. Any suggestions?

Also, can someone maybe explain how it is possible that the mail function can return false yet the email will still get sent? As the PHP manual puts it, the mail function "returns TRUE if the mail was successfully accepted for delivery," or as devinemke puts it, "mail will return true only if the mail was successfully sent to your SMTP app." I understand the opposite case: the email can be accepted by the SMTP server but then still not get sent. But how can the SMTP server send the email out if it was, supposedly, not even successfully accepted by the server? (Or is it actually accepting the email but somehow the wrong message is being communicated to PHP?)

Thanks.