Welcome to Heirloom mailx!
Mailx is derived from Berkeley Mail and is intended provide the
functionality of the POSIX mailx command with additional support
for MIME, IMAP, POP3, SMTP, and S/MIME. It provides enhanced
features for interactive use, such as caching and disconnected
operation for IMAP, message threading, scoring, and filtering.
It is also usable as a mail batch language, both for sending
and receiving mail.
Until March 2006, this project has been developed under the
name "nail"; it is integrated into the Heirloom project now.
The old name will persist at some places. If you were calling
the program under the name "nail" and want to continue to do
so, create a symbolic link to the mailx binary.
New releases of mailx are announced on Freshmeat. If you want to get
notified by email on each release, use their subscription service at
The project homepage is currently at
How to build
To compile and install mailx, look at the file 'INSTALL'. You can also
build mailx RPMs using 'rpmbuild -tb mailx-<version>.tar.bz2'.
You should always install the template for the system-wide configuration
file. If this is not possible because you lack the necessary permissions,
integrate its contents into your ~/.mailrc. This is because some of the
built-in defaults are not appropriate anymore for the Unix platforms of
today, but are still being kept for compatibility.
Mailx has been built successfully in the following environments using
the current configuration system:
Linux Kernel 2.0 and above; libc4, libc5, glibc 2.2 and above,
diet libc, uClibc; gcc, Intel C
Sun Solaris 2.6 and above; Sun C, gcc
Open UNIX 8.0.0
FreeBSD 4.9 and above
HP HP-UX B.11.11, B.11.23; HP C/ANSI C, gcc
HP Tru64 UNIX 4.0G, 5.1B; Developers' Toolkit C, gcc
NetBSD 1.6, 2.0
IBM AIX 5.1; VisualAge C, gcc
Cray UNICOS 22.214.171.124
Control Data EP/IX 2.2.1AA; /svr4/bin/cc
Apple Darwin 6.8
Apple Mac OS X 10.2 Server
NEC UX/4800 Release11.5 Rev.A
NEC SUPER-UX 10.2
If your system does not appear in this list, just try it out. Whether
it works or not, you should contact the development list and report the
But note that I strongly discourage from porting mailx to Windows
and environments that make Windows look Unix-like; I won't accept any
patches or suggestions that go in this direction. There are two major
reasons for this: First, any port makes maintaining harder; there are
always more work-arounds in the source, and introducing new features
involves the question whether they will work an all supported platforms.
The more different a platform behaves from, let's say, the common Unix
way, the more hacks have to be made, costing human time that could
otherwise have been used to enhance the software for Unix platforms.
Windows is just not worth this, and here we are at the second point:
Porting software to Windows encourages people to use -- that is: to buy
-- Windows. It supports a company that is known to threaten Open Source
software like mailx. In short, porting mailx (or similar free software)
to Windows has an ill effect on that software. Don't do it.
Note that my statement doesn't legally restrict you if you want to port
mailx to any platform. This would not be the way of free software either,
especially since I might be wrong in the future; as an example, porting
free software to mainframes of a certain company is considered a good
thing today. I just wish to express my opinion as a free software
developer, and to inform you that I don't maintain such a port.
Mailx supports the mbox and maildir mailbox formats.
The mbox format variant based on the 'Content-Length:' header field that
is used on most SVr4 systems by default is not supported by mailx. As this
format generally is a design flaw, you should fix your system by either
using procmail for local mail delivery, which is a good idea anyway, or
at least add the -E flag to the Mlocal line in /etc/sendmail.cf if using
Although it is not bad, just obsolete, similar considerations apply
to the MMDF format used on OpenServer systems; unless you switch to
procmail (or contribute support for this format), mailx will not be
able to read your mailbox there.
Questions, suggestions, bug reports
Please use the 'nail-devel' mailing list for questions, suggestions,
or bug reports. This has at least three advantages over contacting me
1. Other people can comment on the issue. They might have solved a similar
problem, or might be willing to implement improvements.
2. Since all posts are archived, a problem needs to be commented once only,
and the answers are readily available on the web then.
3. Unless you had an acceptable reason to contact me directly, I will refuse
to give you technical answers by personal mail. Thus if you ignore this
advice, you will just have to resend your message to the list.
Also before you send something to the list, make sure that you did the
1. Check out that you are using a binary made from pristine sources of the
latest release. This is particularly important if you received your mailx
binaries from a third-party vendor. If you are unwilling to do this for
whatever reason, use the support channels of your vendor and avoid abusing
the Open Source development model.
2. Check that your issue is not already solved or commented in the existing
documentation. This does not only involve reading this file; you also
need to look at the manual page and the ChangeLog. After doing that, you
need to search the mailing list archive for related topics. Remember that
you are spending other people's spare time when you ask questions, and
that you just waste it if your question was a superfluous one.
3. If you are reporting a bug, try to reproduce it and include detailed
instructions for doing that in your report. If you cannot reproduce the
bug, document carefully what you have done before the problem occurred.
The more information you provide, the greater are the chances that the
bug can be fixed quickly.
Both the contact instructions and the list archive are available at
<https://lists.sourceforge.net/lists/listinfo/nail-devel>. You need
to subscribe in order to post to the list.
Freiburg i. Br.