Transition of Mail System to the Linux Environment

This document describes changes occurring in the way electronic mail is delivered at a2i communications. Previously mail was delivered in a FreeBSD or SunOS environment. After the transition is complete, all mail delivery will occur in a Linux environment. If you are doing any type of customized mail filtering, then this document will help you understand what changes you might need to make in order to keep your mail flowing without problems.

Although some changes are already occurring, the bulk of the transition is scheduled for: 1:00 pm, Wednesday, December 11, 2002, San Jose local time. Almost all of the changes described in this document will take effect all at once at that time. Please watch our official announcements in the a2i.announce newsgroup or the corresponding mailing list for last-minute updates.

Status of this Document

This is now a historical document. The transition described in this document was completed as scheduled.

Who Should Read This Document

If you use mail only from a pop or imap client, and if you do not ever log into the UNIX shell, then you will most likely not need to read this document. If you do any type of customized mail filtering (e.g., using procmail), you should read this document. If you have customized Nojunk(tm) mail filtering by directly editing a .nojunk.patterns file, then you should read this document.

The Old System

In our old mail system, mail delivery was done in a FreeBSD environment (if Nojunk filtering was not enabled and if you had no .forward file) or in a SunOS environment (if Nojunk filtering was enabled or if you had a .forward file). Also mail arriving for the Nojunk-specific domains was delivered in a SunOS environment. These Nojunk-specific domains are:

email.rahul.net
network.rahul.net
ether.rahul.net
nojunk.rahul.net
spams.r.us.com
*.boxmail.com
*.killspam.us.com
*.usenet.us.com

The New System

In the new mail system, all mail delivery occurs in a Linux environment. The machines on which mail delivery will occur in a Linux environment are:

mauve.rahul.net
violet.rahul.net

Your mail might be delivered on either of these machines.

Differences

Here is a summary of differences between the old and new environments.

No more .forward.bsd files. All mail forwarding will use .forward files only. Any .forward.bsd file in your home directory will be ignored by the new mail system.
Recompilation needed. If you are using any compiled programs (e.g., programs written in C) for mail filtering, you will need to recompile these on a Linux machine. There is no need to recompile interpreted programs (e.g., perl and shell scripts), but you should test your scripts to make sure they work in our Linux environment.
Procmail always runs. In the new Linux environment, the procmail program is always used to do final mail delivery, and any .procmailrc file in your home directory is always used for filtering. This is different from the behavior of the old system, in which procmail ran only if you invoked it from a .forward or .forward.bsd file or via a pipe statement in a .nojunk.patterns file.
Only email addresses in .forward files. In the new environment, if you wish to feed incoming mail to a program, you may do so by invoking that program from within a .procmailrc file. Pipe commands within .forward files are not supported. Also filenames (for file append) are not supported within .forward files. You may use only email addresses in a .forward file. Check any .forward or .forward.bsd file in your home directory. If there is any ``|'' (vertical bar) character in one of these files, you are probably running a program which must be moved out of this file into a .procmailrc file.
Program locations differ. Program locations in the Linux environment are not necessarily the same as in the FreeBSD and SunOS environments. Thus you should verify that all programs invoked in your files related to mail filtering are valid in the Linux environment. Where possible, avoid using absolute pathnames, so that procmail can find the program by simply looking in the standard places. Please note that the correct location of the sendmail program is now /usr/sbin/sendmail on all machines, including SunOS, FreeBSD, and Linux. As a transition aid, we have made the following programs available in the SunOS, FreeBSD, and Linux environments at exactly the same locations:
- /usr/bin/formail
- /usr/bin/procmail
- /usr/local/bin/perl5
If you have any scripts that need to invoke these programs with full pathnames, you may edit them now to use the above pathnames. Then, when the transition occurs, you will not need to change these pathnames again.
Recipient in X-Original-To. In the past, most users relied on looking for a Received: header in email to find the address of the recipient. In the new system, a header X-Original-To: will appear in all incoming email that will identify the recipient address.
No vacation program. The vacation program available in the SunOS and FreeBSD environments is not directly available in the Linux environment. You may get the same functionality with procmail. Please see the online manual called procmailex(5), which you can read by typing the command ``man procmailex(5)'' at the UNIX shell on a Linux machine. Look for an autoreply recipe that works the same way as the vacation program.

Pre-Transition Testing

Before the transition, you can test mail delivery in the new Linux environment by simply sending mail to USER@linux.rahul.net, where USER is your login name. Such test mail will be delivered in a Linux environment. For these tests, any .forward and .forward.bsd files will be ignored, but any .forward.linux file will be active. No Nojunk processing will occur.

This feature is for pre-transition testing only.

Playing it Safe

The safest way to survive the transition with the greatest chance of not losing mail is to disable any mail forwarding, any mail filters, and any Nojunk features, well in advance of the change. Then all your incoming mail will go into your mailbox. Then, after the change is completed and the new mail system is known to be stable, you may carefully re-enable the above features.

Troubleshooting

If during or after the mail system transition you report a mail problem to us, this is the sequence of steps that we will follow.

We will disable any Nojunk filtering that might have been active for you.
We will move any .forward file in your home directory to a temporary name such as .forward.SAVE.
We will then check to see if your mail is being properly delivered into your mailbox. If it is, the problem will be considered resolved in the short run. Then you may at your convenience re-enable any Nojunk filtering or any mail forwarding carefully. (Note: If your account type does not include a local mailbox, then we will leave your mail forwarding enabled and we will verify that mail is being correctly forwarded.)
If any problems related to Nojunk filtering or mail forwarding are observed, and they appear to be due to a problem in our mail system and not in your own account-specific files, those issues will be addressed system-wide.

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