Domain names are used to uniquely name each host on the Internet. A domain name has a number of parts separated by periods. Each label represents a level in the hierarchy. An example of a name is:
In this domain name the top-level label is edu, indicating it is at an educational institution, the second-level label is washington, indicating the University of Washington. cac is a specific department within the University of Washington, and olive is the host name. The top-level names are assigned by Internet organizations, and other names are assigned at the appropriate level. The Domain Name Service, DNS, is the distributed database used to look up these names.
Pine relies on domain names in multiple places. A domain name is embedded into the message-id line generated for each piece of email. A domain name is needed to contact an IMAP server to get access to remote INBOXes and folders. Most importantly, domain names are needed to construct the From: line of your outgoing messages so that people on the Internet will be able to get email back to you.
On UNIX systems, you can set the domain via the user-domain
variable in the Pine configuration file, or rely on the file
/etc/hosts which usually sets the name of the local host.
While Pine can often deliver email without the domain name being properly
configured, it is best to have this set right. Problems can usually be
solved by adjusting the system's entry in the
file. The fully-qualified name should be listed before any abbreviations.
is preferred over
220.127.116.11 olive.cac.washington.edu olive
18.104.22.168 olive olive.cac.washington.edu
On PCs, the task of configuring the domain name is a bit different. Often times, PCs do not have domain names-they have IP addresses. IP addresses are the numbers which uniquely identify a computer on the network. The way you configure your IP address depends on the networking software which you use on the PC. You can refer to the documentation which came with your networking software or see the PC specific installation notes for help configuring the IP address with your network software.
With PCs, it is vital that users set the variable user-domain in the Pine
configuration file (
Details on configuring Pine with correct domain names can be found in the Domain Settings section of this document.
As far as outgoing email is concerned, Pine fully-qualifies addresses whenever possible. They are even displayed in fully-qualified form on the terminal as the user composes a message. This makes addresses more clear and gives a hint to the user that the network extends beyond the local organization. Pine implements fully-qualified domain names by tacking on the local domain to all unqualified addresses which a user types in. Any address which does not contain a "@" is considered unqualified.
The newer format for addresses allow for spaces and special characters in the full name of an address. For this reason, commas are required to separate addresses. If any special characters as defined in RFC 822 appear in the full name, quotes are required around the address. Pine will insert the quotes automatically. The common cases where this happens are with periods after initials and parentheses.
Because Pine fully complies with RFC 822, it is sometimes difficult to use
non-Internet address formats such as UUCP's
USER::HOST with Pine. People who run Pine on these
systems have made local modifications to Pine or to the mail transport
agent (e.g. sendmail) to make things work for them. Another special case
that Pine does not allow for are the sites in the United Kingdom which
require two "local" domains (one in the form machine.site.ac.uk
for use outside the UK and the other uk.ac.site.machine for use
inside the UK). This special case requires local modifications to Pine.
Pine expects dates to be in the standard RFC 822 format which is something like:
[www, ] dd mmm yy hh:mm[:ss] [timezone]It will attempt to parse dates that are not in this format. When an unparsable date is encountered it is displayed as xxx xx when shown in the FOLDER INDEX screen.
All outgoing email is delivered to a mail transfer program or to an SMTP
server. The most common mail transfer program is
sendmail, it first writes the message to a temporary file in
/tmp. Then Pine runs a shell in the background that runs
sendmailon the temporary file and then removes it. This is done with a shell in the background so the user doesn't have to wait for
sendmailto finish. By default,
sendmailis invoked with the
-tflag to cause it to read and parse the header to determine the recipients; the
-oemflag to cause errors to be mailed back; and the
-oiflag to ignore dots in incoming messages. Systems administrators can choose to configure Pine to use a different mail transfer program or even
sendmailwith different flags. See the section on UNIX Pine Compile-time Options for more details on this.
Pine can also operate as an SMTP client. SMTP stands for Simple Mail Transfer Protocol; it specifies the rules by which computers on the Internet pass email to one another. In this case, Pine passes outgoing email messages to a designated SMTP server instead of to a mail transfer program on the local machine. A program on the server then takes care of delivering the message. To make Pine operate as an SMTP client, the smtp-server variable must be set to the IP address or host name of the SMTP server within your organization. This variable accepts a comma separated list of servers, so you can specify multiple SMTP servers. PC-Pine only runs as an SMTP client.
smtp-server, and compile-time options. The first MTA specified in the following list is used:
sendmail-pathspecified on the command line.
smtp-serverspecified on the command line.
sendmail-pathin the user's
smtp-serverin the user's
DF_SENDMAIL_PATHdefined at compile time.
SENDMAILFLAGSdefined at compile time.
sendmail-path form is used, a child process is
forked, and the specified command is executed with the message passed on
standard input. Standard output is then passed back and displayed for
smtp-server is specified, a connection to the server is
opened. If the message contains 8-bit text, ESMTP 8BITMIME negotiation is
attempted. The message is then sent using SMTP commands.
If none of the above are set, the default
sendmail program is
invoked with the "
-bs -odb -oem" flags, ESMTP negotiation is
attempted, and the message is sent.
Pine 3.92 is an IMAP2bis client, but does not yet implement all of the IMAP4 extensions. (IMAP2bis was an interim specification superseded by IMAP4.) Pine takes advantage of the extensions defined in IMAP2bis for efficient and selective access to MIME body parts. We expect the next major release of Pine (probably version 4.0) to be fully compatible with the IMAP4 specification.
The MIME standard was officially published in June of 1992 as RFC 1341 and subsequently revised in RFC 1521 when it became a full Internet Standard. Pine 3.0 was one of the first email programs to Implement MIME. Now, there are dozens of commercial and freely available MIME-capable email programs. In addition, MIME is being added to newsreaders so MIME messages can be posted and read in USENET newsgroups.
The MIME standard also includes support for non-ASCII text in message headers through the extensions described in RFC 1342 and subsequently revised in RFC 1522. Support for RFC 1522 was added in Pine 3.92.
An actual MIME message looks something like this:
Date: Tue, 12 Mar 1996 15:39:35 -0800 (PST) From: David L Miller <firstname.lastname@example.org> To: David L Miller <email@example.com> Subject: =?iso-8859-1?Q?Test_MIME_message_with_RFC-1522_headers_=28=E1?= =?iso-8859-1?Q?=E2=E3=29?= Message-Id: <Pine.ULT.3.92.960312150851.21583Ifirstname.lastname@example.org> Mime-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="0-1737669234-826673975=:21583" Content-Id: <Pine.ULT.3.92.960312153928.21583O@shiva2.cac.washington.edu> This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. Send mail to email@example.com for more info. --0-1737669234-826673975=:21583 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-ID: <Pine.ULT.3.92.960312153104.21583L@shiva2.cac.washington.edu> The text of the message would go here. It is readable if one doesn't mind wading around a little bit of the MIME formatting. After this is a binary file in base 64 encoding. |\ | |\/| David L. Miller firstname.lastname@example.org (206) 685-6240 |/ |_ | | Software Engineer, Pine Development Team (206) 685-4045 (FAX) University of Washington, Networks & Distributed Computing, JE-20 4545 15th Ave NE, Seattle WA 98105, USA --0-1737669234-826673975=:21583 Content-Type: APPLICATION/ZIP; NAME="test.zip" Content-Transfer-Encoding: BASE64 Content-ID: <Pine.ULT.3.92.960312153638.21583N@shiva2.cac.washington.edu> Content-Description: Test Attachment UEsDBBQAAAAIAGh8bCBbZKT4ygIAAHgFAAAEAAAAdGVzdIVUX2vbMBB/16c4 9rSBNyjsYX1UHSUROLInycv2qNhKI5ZYxlLa5dvvpDRLw6CFgJF09/t3Rxo3 WDBDD43rPJjJQpxMbw9m+h3AbyHuLLSDe7JTcPGUbtYm7NzwGP3wBYQnnT8c 7NQ5s4djsC8t4QbmYE6wsfjpLTy7uPPHCOPk/ATPk4vRDmS008GF4PzwPich zY3m4LfxOQlPNy4GcEO3P/a2h2j/xGyp9ONpco+7CHf33+4/393ff4XNibzL c1UVfXJXQIdIBRx877b4TYy9C3Fym2NEyzsX/pNDet8dD3aIJiagLbo2wwnG 4zT6cK66ZLK1NhH9J4tcZQEy7OxkNyd4nMwQbV9glP7JZb87E3O32fgnm7We XQ8+us4SM47WTCkgMPt9enc2ZAW5c+Pj7o32l0IXXk/r8pSRE3A4jqOfIqqF G+PFlSdRDOaQduXNESTwtDcYfJ8191gWXUjYmOJ43Oxdh11JTzRuSPcY37+B vNqmf0O5RB1G27mt64rLCp4X8pW1L6BvxunCeYHNk3F7s9lb+GAwyvAhOyNE Lxm0gv9gUnH9C+o5rKlacrHQtYAZV2VF+UoBrSp8kJIKzZkqgP1sJFMKagl8 1VSczQqy5noJki2onIGuQS+5AlXPNfaxArgoq3aGwJDq6lZDxVdcU82RKMG/ 4JArTVKzYrJc4pE+8CoJpGIGc65FIp8jO4WGSs3LtqISmlY2tUKyVMUFETWw H0xoUMvE8KbXB4aC6EPFzrDiF6iGlZxWBeFixiUrdXJb1kKx7y2C4hPM6Iou WI4hdVyO6yXVqkZqiXmottLJ9lzWK1LVKttqk8oZ1TS1NrJGS5jqeslQI0aK ieCvzNlgNZJqiccCc5WafLxmKdii4gsmSvYpISkteamzkRwXJiG5SoUpcERK 8xIE8QQ7o+eh5WAUy1qYRP8rioip/maI+OfyF1BLAQIUAxQAAAAIAGh8bCBb ZKT4ygIAAHgFAAAEAAAAAAAAAAEAAACkgQAAAAB0ZXN0UEsFBgAAAAABAAEA MgAAAOwCAAAAAA== --0-1737669234-826673975=:21583--For details about Pine's implementation of MIME, see the two MIME sections "MIME: Reading a Message" and "MIME: Sending a Message" later in this document.
Currently, Pine has no way to dynamically create or define collections, but there is much work still going on in this area. The hope is to provide a general way to define, display and navigate remote folder collections in a consistent way across platforms and applications. Especially important to this goal will be the hierarchy support provisions in the IMAP4 specification. Stay tuned!
For a more complete description of Folder Collections, see the section on "Syntax for Collections."
The Pine distribution is designed to require as little configuration and effort at compile time as possible. Still, there are some Pine behaviors which are set at the time you compile Pine. For each of these, there is a reasonable (our opinion) default built into the code, so most systems administrators will have no need for these steps.