Channel configuration strings

Mail and Messaging Guide
Chapter 4, Managing mail with MMDF

MMDF uses channel configuration strings to obtain detail information about the channel. Only the uucp and smtp channels utilize configuration strings.

Specify configuration strings, when adding or modifying a channel.

The uucp configuration string

The default uucp channel configuration string specifies the number of addresses a host can handle in a single mail command. The default value is 1. The syntax of the string is:

   naddrs=N

N is the specified number of addresses.

UUCP parameters include:

naddrs

the maximum number of addresses the uucp channel puts in a single uux(C) command. The default is 1 for backwards compatibility with older UUCP systems, which can process only one address at a time.

If you know that all sites with which you exchange mail via UUCP can handle more than one address, you can set naddrs to a higher value. Alternatively, you can create a second UUCP channel, with naddrs set to a larger value, for those UUCP sites that can handle more addresses.

maxlen

the maximum length of a uux command-line. The default value for maxlen is 1024. SCO recommends against raising the value of maxlen.

rewrite

controls how addresses are rewritten when being used as arguments to the rmail(ADM) command on a remote machine.

The possible values are:

 rewrite=976   uses RFC 976 address format
 rewrite=822   uses RFC 822 address format
 rewrite=733   uses RFC 733 address format

The default value for rewrite is 976.

When using RFC 976 address format, addresses are rewritten as:

 -------------------------------------------------
 Address                    Rewritten as
 -------------------------------------------------
 host1!host2!host3!user     host1!host2!host3!user 
 user%host3%host2@host1     host1!host2!host3!user 
 @host1,@host2:user@host3   host1!host2!host3!user

Simpler addresses, such as the most commonly-used user@host, are left alone except under RFC 976, where they are rewritten as host!user.

When using RFC 822 address format, addresses are rewritten as:

 ---------------------------------------------------
 Address                    Rewritten as
 ---------------------------------------------------
 host1!host2!host3!user     host1!host2!host3!user 
 user%host3%host2@host1     user%host3%host2@host1 
 @host1,@host2:user@host3   @host1,@host2:user@host3

When using RFC 733 address format, addresses are rewritten as:

 -------------------------------------------------
 Address                    Rewritten as
 -------------------------------------------------
 host1!host2!host3!user     host1!host2!host3!user 
 user%host3%host2@host1     user%host3%host2@host1 
 @host1,@host2:user@host3   user%host3%host2@host1

The smtp configuration string

The default smtp channel configuration string specifies the SMTP name of the host and the character set to be used. The syntax of the string is:

   hostname=hostname, charset=[7,8]bit

hostname is the name of the host for SMTP protocol. This name is used in ``Received:'' headers and is required by some SMTP implementations. The default is to assign the value of the MMDF hostname (for example, mynet.com).

The value of charset specifies whether messages contain 7- or 8-bit data. Using the 8-bit setting violates the SMTP protocol standard specified by the Internet technical bulletin, RFC 821, (available from the InterNIC Registration Services, or InterNIC; see ``Registering domain names''). However, the 8-bit setting is widely used in Europe. The default value is 7-bit.