SMM:08-62
Sendmail Installation and Operation Guide
ClientCertFile
[no short name] File containing the certificate of the client, i.e., this certificate is
used when sendmail acts as client (for STARTTLS).
ClientKeyFile
[no short name] File containing the private key belonging to the client certificate
(for STARTTLS if sendmail runs as client).
ClientPortOptions=options
[O] Set client SMTP options. The options are key=value pairs separated by com-
mas. Known keys are:
Port
Name/number of source port for connection (defaults to any free port)
Addr
Address mask (defaults INADDR_ANY)
Family
Address family (defaults to INET)
SndBufSize
Size of TCP send buffer
RcvBufSize
Size of TCP receive buffer
Modifier
Options (flags) for the client
The Address mask may be a numeric address in dot notation or a network name.
Modifier can be the following character:
h
use name of interface for HELO command
A
don't use AUTH when sending e-mail
S
don't use STARTTLS when sending e-mail
If ``h'' is set, the name corresponding to the outgoing interface address (whether
chosen via the Connection parameter or the default) is used for the HELO/EHLO
command. However, the name must not start with a square bracket and it must
contain at least one dot. This is a simple test whether the name is not an IP
address (in square brackets) but a qualified hostname. Note that multiple Client-
PortOptions settings are allowed in order to give settings for each protocol family
(e.g., one for Family=inet and one for Family=inet6). A restriction placed on one
family only affects outgoing connections on that particular family.
ColonOkInAddr [no short name] If set, colons are acceptable in e-mail addresses (e.g.,
"host:user"). If not set, colons indicate the beginning of a RFC 822 group con-
struct ("groupname: member1, member2, ... memberN;"). Doubled colons are
always acceptable ("nodename::user") and proper route-addr nesting is under-
stood ("<@relay:user@host>"). Furthermore, this option defaults on if the con-
figuration version level is less than 6 (for back compatibility). However, it must
be off for full compatibility with RFC 822.
ConnectionCacheSize=N
[k] The maximum number of open connections that will be cached at a time. The
default is one. This delays closing the current connection until either this invoca-
tion of sendmail needs to connect to another host or it terminates. Setting it to
zero defaults to the old behavior, that is, connections are closed immediately.
Since this consumes file descriptors, the connection cache should be kept small: 4
is probably a practical maximum.
ConnectionCacheTimeout=timeout
[K] The maximum amount of time a cached connection will be permitted to idle
without activity. If this time is exceeded, the connection is immediately closed.
This value should be small (on the order of ten minutes). Before sendmail uses a
cached connection, it always sends a RSET command to check the connection; if
this fails, it reopens the connection. This keeps your end from failing if the other
end times out. The point of this option is to be a good network neighbor and
avoid using up excessive resources on the other end. The default is five minutes.