TORONTO USERS GROUP
for Midrange Systems
TUG eServer magazine July
1996: Volume 11, Number 6
E-MAIL Unleashed -
OS/400 POP and MIME Support
The World
Wide Web may be the fanciest part of the Internet; newsgroups
may be the most controversial; and search engines may be the hottest
stocks around, but when it comes to making the Internet truly
useful you can't beat electronic mail. While OS/400 has had an
SMTP gateway for some time, the newly announced Version 3 Release
2/7 has enhanced e-mail capability with a POP3 server and support
for the MIME extensions.
POP stands for Post Office Protocol. The idea behind
POP is simply disconnected mail. If you only connect to the network
every once in a while, you need a place to store your mail until
you can pick it up. The POP server provides that mailbox function.
It stores the mail until you connect, then downloads all your
mail to your client machine. All of the mail processing, such
as reading, filing, replying, and so on, are performed on your
client system.
One of the advantages of using POP for mail distribution
is the availability of POP clients. There is POP client code for
UNIX systems, Macintosh, OS/2, DOS and Windows. This means that
you can offer your users an e-mail system that continues to
use the AS/400 server that you've got in the office already, with
its reliability and ease of management, but with a client like
Eudora or any of the other popular POP clients.
How does this work? The POP server is a store-and-forward
mail system that provides electronic mailboxes on the AS/400 from
which a POP client can retrieve mail. It uses the AnyMail/400
mail server framework along with the system distribution directory
to process and distribute e-mail. It uses the simple mail transfer
protocol (SMTP) to forward mail. The POP server is only a temporary
holding area for mail. Once the client has connected and retrieved
its mail, the POP server deletes those messages.
When using OV/400 to send mail, you need a directory
entry for every user to whom you want to send mail, as well as
one for every user who wishes to receive mail. This all right
as long as you only want to communicate with people within your
own organization because it is possible to keep track of all your
own users. You need to do this anyway, because you probably want
to manage their access to applications on your system. However,
when you want to communicate with the rest of the world, this
requirement becomes a management headache. A POP client, on the
other hand, using SMTP can send mail to any remote SMTP user without
having a directory entry for each user. With V3R2(CISC) &
V3R7(RISC), you can tell OS/400 to use SMTP instead of SNADS to
deliver the mail by changing two new parameters: the Mail Service
Level and Preferred Address.
Another new function of V3R2/7 is something called
MIME. MIME stands for Multi-purpose Internet Mail Extensions,
but for most people, it means the ability to attach binary objects
like video, image, audio or files like spreadsheets and word processing
documents to your mail message. The POP server can figure out
what to do with the attachment, so your POP clients will receive
their MIME attachments just fine. What about your OV/400 users?
AnyMail/400 server framework steps in again to handle
this. A MIME conversion function converts any MIME text attachments
into an OV/400 note and converts any binary attachments into documents
with a type of "IBM Personal Computer File". References
to the attachments are placed in the OV/400 note, so that the
recipient can tell that there are some binary files to look for.
With V3R2 & V3R7, the POP server and MIME support
have greatly extended the E-mail capability of OS/400. It may
not be glamorous, it may not be controversial, and it probably
won't make the front cover of Infobabble Weekly, but true to the
design of the AS/400, it sure is useful.
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