patch against NUL chars

[Simon Brady]

On Thu, 8 May 2003, Nikola Milutinovic wrote:

> Is there a legitimate reason for NUL chars in an e-mail message?

Not as far as I know.

> If not, how are they getting there?

Goblin mischief? After upgrading our site of ~15-18K users to cyrus 2.1 we 
started seeing 1-2 messages with NULs a week, but were never able to 
conclusively determine the cause. Broken clients is the most obvious 
answer, but why so intermittently?

> And why should you give a damn?

It gets a bit messy when sendmail tries to report the "message contains 
NULs" DSN to postmaster and includes the original message... Luckily the 
message is dropped with a "losing queue" comment rather than looping.

The quick solution we adopted, courtesy of someone on this list, was to
upgrade to sendmail 8.12 and use the F=1 delivery agent flag to strip NULs 
before lmptd even saw the messages (see p748 of the Bat Book, 3rd ed). 
This solved the problem without having to touch cyrus.

--
Simon Brady                             mailto:simon.brady at otago.ac.nz
ITS Technical Services
University of Otago, Dunedin, New Zealand