I am using PHP 4.0.6 (the same applies with version 4.0.5) on Windows 2000. I have written a page where someone can send MIME mail including multiple attachments. The attachments go into the header parameter of the mail() function. The bug I'm reporting is that when the attached part(s) are more than 2KB in size, the mail() function crashes and together PHP.exe. I believe there must be some unreasonable limitation in the size of the header parameter. I don't know if this problem exists in Unix environments, but I know at least another developer who has reported the same problem on the Windows platform.