sendmail 8.9.3 on HPUX 11i

[Jeff Davis_1]

When addressing mail to external users, the message will contain headers that include "To:", "CC:" and "BCC:". These headers will include the user display and the user mail address in the form "User Name ". Multiple entries will be separated by semi-colons. The entity sending mail (Exchange or mail programs on other servers) are required to wrap these headers on multiple lines if the line length exceeds 72 characters. A multiple line "To:" or "CC:" header will look like:

To: Some User with a Very Long Name or Perhaps Multiple Users

Cc: One User Name ;
Another User with possible another very long name


When the HP implementation of sendmail receiving a message containing recipient headers ("To:", "CC:", etc.), where those headers are line-wrapped, it fails to terminate internal buffers with a correct line terminator (a NUL character, '\0'). The result is that it outputs the re-formatted message with recipient headers that contain extra garbage characters after the address. On some receiving mail systems, the To: and CC: lines appear garbled, or to contain extra characters. Some receiving mail systems reject the message outright, and refuse to deliver it.

If I send this message with the header formatted as:

To: username

it goes through. If I send this message with the header formatted as:

To: username in belgium


the target server rejects it because of extra characters (it actually reports "Header too long"). What we see on the receiving end is that extra characters are embedded in the output when the HP sendmail process delivers it to the far end server.

Anyone seen this before?