On Sat, 2008-12-06 at 12:41 -0800, Gordon Messmer wrote:

Excellent. Thank you! I was thinking I ought to be able to strace this but had forgotten that one could attach strace to a running process. Here's the output:

[pid 5682] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or
directory) [pid 5682]
open("/usr/lib64/courier-authlib/tls/x86_64/libcourierauthsaslclient.so",
O_RDONLY) = -1 ENOENT (No such file or directory) [pid 5682] stat("/usr/lib64/courier-authlib/tls/x86_64", 0x7fff8cde5e40) = -1
ENOENT (No such file or directory) [pid 5682] open("/usr/lib64/courier-authlib/tls/libcourierauthsaslclient.so",
O_RDONLY) = -1 ENOENT (No such file or directory) [pid 5682] stat("/usr/lib64/courier-authlib/tls", 0x7fff8cde5e40) = -1 ENOENT
(No such file or directory) [pid 5682]
open("/usr/lib64/courier-authlib/x86_64/libcourierauthsaslclient.so", O_RDONLY)
= -1 ENOENT (No such file or directory) [pid 5682] stat("/usr/lib64/courier-authlib/x86_64", 0x7fff8cde5e40) = -1
ENOENT (No such file or directory) [pid 5682] open("/usr/lib64/courier-authlib/libgdbm.so.3", O_RDONLY) = -1
ENOENT (No such file or directory) [pid 5682] open("/usr/lib64/courier-authlib/libdl.so.2", O_RDONLY) = -1 ENOENT
(No such file or directory) [pid 5682] open("/usr/lib64/courier-authlib/libc.so.6", O_RDONLY) = -1 ENOENT
(No such file or directory) [pid 5682] open("/etc/courier/esmtptimeoutkeepalive", O_RDONLY) = -1 ENOENT (No
such file or directory) [pid 5682] open("/etc/courier/esmtptimeoutkeepaliveping", O_RDONLY) = -1 ENOENT
(No such file or directory) [pid 5682] open("/etc/courier/esmtptimeoutconnect", O_RDONLY) = -1 ENOENT (No
such file or directory) [pid 5682] open("/etc/courier/esmtptimeoutquit", O_RDONLY) = -1 ENOENT (No such
file or directory) [pid 5682] open("/etc/courier/esmtphelo", O_RDONLY) = -1 ENOENT (No such file
or directory) [pid 5684] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or
directory) [pid 5684] open("/etc/ssl/cert.pem", O_RDONLY) = -1 ENOENT (No such file or
directory) [pid 5684] stat("/etc/ssl/certs/c33a80d4.1", 0x7fff935ca8f0) = -1 ENOENT (No
such file or directory)

Since processes frequently iterate through a series of possible locations for needed files, plus many that aren't needed but just checked for, I assume most of these are spurious, and the last one is probably the one that's causing the problem.

Indeed, there is no c33a80d4.1 cert file. I'm not familiar with the details of the TLS mechanism. Is this a file that's expected to be there as a result of the TLS negotiation with the remote server?