Frequently Asked Questions
This FAQ is specific to Version 8 of sendmail. Other questions,
particularly regarding compilation and configuration, are answered
in src/READ_ME and cf/README.
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* Where can I get Version 8?
Via anonymous FTP from FTP.CS.Berkeley.EDU in /ucb/sendmail.
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* What are the differences between Version 8 and other versions?
See doc/changes/changes.me in the sendmail distribution.
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* What happened to sendmail 6.x and 7.x?
When I released a new version of sendmail, I changed it to
Release 6. Development continued in that tree until 4.4BSD
was released, when everything on the 4.4 tape was set to be
version 8.1. Version 7.x never existed.
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* Version 8 requires a new version of "make". Where can I get this?
Actually, Version 8 does not require a new version of "make".
It includes a collection of Makefiles for different architectures,
only one or two of which require the new "make". If you are
porting to a new architecture, start with Makefile.dist.
If you really do want the new make, it is available on any of
the BSD Net2 or 4.4-Lite distribution sites. These include:
ftp.uu.net /systems/unix/bsd-sources
gatekeeper.dec.com /.0/BSD/net2
ucquais.cba.uc.edu /pub/net2
ftp.luth.se /pub/unix/4.3bsd/net2
Diffs and instructions for building this version of make under
SunOS 4.1.x are available on ftp.css.itd.umich.edu in
/pub/systems/sun/Net2-make.sun4.diff.Z.
There is also a Linux version available on the main Linux
distribution sites as pmake; this version is included as
standard with the current Slackware distributions.
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* What macro package do I use to format the V8 man pages?
The BSD group switched over the the ``mandoc'' macros for
the 4.4 release. These include more hooks designed for
hypertext handling. However, new man pages won't format
under the old man macros. Fortunately, old man pages will
format under the new mandoc macros.
Get the new macros with the BSD Net2 or 4.4-Lite release.
This macro set is also available with newer versions of groff.
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* What books are available describing sendmail?
There is one book available devoted to sendmail:
Costales, Allman, and Rickert, _Sendmail_. O'Reilly &
Several books have sendmail chapters, for example:
Nemeth, Snyder, and Seebass, _Unix System Administration
Handbook_. Prentice-Hall.
Carl-Mitchell and Quarterman, _Practical Internetworking with
TCP/IP and UNIX_. Addison-Wesley.
Hunt, _TCP/IP Network Administration_. O'Reilly & Associates.
Another book about sendmail is due out "soon":
Avolio & Vixie, _Sendmail Theory and Practice_. Digital
Press (release date unknown).
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* How do I make all my addresses appear to be from a single host?
Using the V8 configuration macros, use:
MASQUERADE_AS(my.dom.ain)
This will cause all addresses to be sent out as being from
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* How do I rewrite my From: lines to read ``First_Last@My.Domain''?
There are a couple of ways of doing this. This describes using
the "user database" code. This is still experimental, and was
intended for a different purpose -- however, it does work
with a bit of care. It does require that you have the Berkeley
"db" package installed (it won't work with DBM).
First, create your input file. This should have lines like:
loginname:mailname First_Last
First_Last:maildrop loginname
Install it in (say) /etc/userdb. Create the database:
makemap btree /etc/userdb.db < /etc/userdb
You can then create a config file that uses this. You will
have to include the following in your .mc file:
define(confUSERDB_SPEC, /etc/userdb.db)
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* So what was the user database feature intended for?
The intent was to have all information for a given user (where
the user is the unique login name, not an inherently non-unique
full name) in one place. This would include phone numbers,
addresses, and so forth. The "maildrop" feature is because
Berkeley does not use a centralized mail server (there are a
number of reasons for this that are mostly historic), and so
we need to know where each user gets his or her mail delivered --
We are in the process of setting up our environment so that
mail sent to an unqualified "name" goes to that person's
preferred maildrop; mail sent to "name@host" goes to that
host. The purpose of "FEATURE(notsticky)" is to cause
"name@host" to be looked up in the user database for delivery
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* Why are you so hostile to using full names for e-mail addresses?
Because full names are not unique. For example, the computer
community has two Andy Tannenbaums and two Peter Deutsches.
At one time, Bell Labs had two Stephen R. Bournes with offices
a few doors apart. You can create alternative addresses
(e.g., Stephen_R_Bourne_2), but that's even worse -- which
one of them has to have their name desecrated in this way?
And you can bet that they will get most of the other person's
So called "full names" are just longer versions of unique
names. Rather that lulling people into a sense of security,
I'd rather that it be clear that these handles are arbitrary.
People should use good user agents that have alias mappings
so that they can attach arbitrary names for their personal
use to those with whom they correspond.
Even worse is fuzzy matching in e-mail -- this can make good
addresses turn bad. For example, I'm currently (to the best
of my knowledge) the only ``Allman'' at Berkeley, so mail
sent to "Allman@Berkeley.EDU" should get to me. But if
another Allman ever appears, this address could suddenly
become ambiguous. I've been the only Allman at Berkeley for
over fifteen years -- to suddenly have this "good address"
bounce mail because it is ambiguous would be a heinous wrong.
Finger services should be as fuzzy as possible. Mail services
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* When I use sendmail V8 with a Sun config file I get lines like:
/etc/sendmail.cf: line 273: replacement $3 out of bounds
the line in question reads:
R$*<@$%y>$* $1<@$2.LOCAL>$3 user@ether
what does this mean? How do I fix it?
V8 doesn't recognize the Sun "$%y" syntax, so as far as it
is concerned, there is only a $1 and a $2 (but no $3) in this
line. Read Rick McCarty's paper on "Converting Standard Sun
Config Files to Sendmail Version 8", in the contrib directory
(file "converting.sun.configs") on the sendmail distribution
for a full discussion of how to do this.
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* Should I use a wildcard MX for my domain?
Wildcard MX records have lots of semantic "gotcha"s. For
example, they will match a host "unknown.your.domain" -- if
you don't explicitly test for unknown hosts in your domain,
you will get "config error: mail loops back to myself"
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* I'm connected to the network via a SLIP link. Sometimes my sendmail
process hangs (although it looks like part of the message has been
transfered). Everything else works. What's wrong?
Most likely, the problem isn't sendmail at all, but the low
level network connection. It's important that the MTU (Maximum
Transfer Unit) for the SLIP connection be set properly at both
ends. If they disagree, large packets will be trashed and
the connection will hang.
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* I just upgraded to 8.x and suddenly I'm getting messages in my
syslog of the form "collect: I/O error on connection". What is
Nothing. This is just a diagnosis of a condition that had
not been diagnosed before. If you are getting a lot of these
from a single host, there is probably some incompatibility
between 8.x and that host. If you get a lot of them in general,
you may have network problems that are causing connections to
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* How can I get sendmail to deliver local mail to $HOME/.mail
instead of into /usr/spool/mail (or /usr/mail)?
This is a local mailer issue, not a sendmail issue. Either
modify your local mailer (source code will be required) or
change the program called in the "local" mailer configuration
description to be a new program that does this local delivery.
I understand that "procmail" works well, although I haven't
You might be interested in reading the paper ``HLFSD: Delivering
Email to your $HOME'' available in the Proceedings of the
USENIX System Administration (LISA VII) Conference (November
1993). This is also available via public FTP from
ftp.cs.columbia.edu:/pub/hlfsd/{README.hlfsd,hlfsd.ps}.
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* Under V8, the "From " header gets mysteriously munged when I send
``It's not a bug, it's a feature.'' This happens when you have
a "owner-list" alias and you send to "list". V8 propogates the
owner information into the envelope sender field (which appears
as the "From " header on UNIX mail or as the Return-Path: header)
so that downstream errors are properly returned to the mailing
list owner instead of to the sender. In order to make this
appear as sensible as possible to end users, I recommend making
the owner point to a "request" address -- for example:
list: :include:/path/name/list.list
This will make message sent to "list" come out as being
"From list-request" instead of "From eric".
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* There are four UUCP mailers listed in the configuration files.
The choice is partly a matter of local preferences and what is
running at the other end of your UUCP connection. Unlike good
protocols that define what will go over the wire, UUCP uses
the policy that you should do what is right for the other end;
if they change, you have to change. This makes it hard to
do the right thing, and discourages people from updating their
software. In general, if you can avoid UUCP, please do.
If you can't avoid it, you'll have to find the version that is
closest to what the other end accepts. Following is a summary
of the UUCP mailers available.
uucp-old (obsolete name: "uucp")
This is the oldest, the worst (but the closest to UUCP) way of
sending messages accros UUCP connections. It does bangify
everything and prepends $U (your UUCP name) to the sender's
address (which can already be a bang path itself). It can
only send to one address at a time, so it spends a lot of
time copying duplicates of messages. Avoid this if at all
uucp-new (obsolete name: "suucp")
The same as above, except that it assumes that in one rmail
command you can specify several recipients. It still has a
This UUCP mailer keeps everything as domain addresses.
Basically, it uses the SMTP mailer rewriting rules.
Unfortunately, a lot of UUCP mailer transport agents require
bangified addresses in the envelope, although you can use
domain-based addresses in the message header. (The envelope
shows up as the From_ line on UNIX mail.) So....
This is a cross between uucp-new (for the envelope addresses)
and uucp-dom (for the header addresses). It bangifies the
envelope sender (From_ line in messages) without adding the
local hostname, unless there is no host name on the address
at all (e.g., "wolf") or the host component is a UUCP host name
instead of a domain name ("somehost!wolf" instead of
We are on host grasp.insa-lyon.fr (UUCP host name "grasp"). The
following summarizes the sender rewriting for various mailers.
Mailer sender rewriting in the envelope
------ ------ -------------------------
uucp-{old,new} wolf grasp!wolf
uucp-dom wolf wolf@grasp.insa-lyon.fr
uucp-uudom wolf grasp.insa-lyon.fr!wolf
uucp-{old,new} wolf@fr.net grasp!fr.net!wolf
uucp-dom wolf@fr.net wolf@fr.net
uucp-uudom wolf@fr.net fr.net!wolf
uucp-{old,new} somehost!wolf grasp!somehost!wolf
uucp-dom somehost!wolf somehost!wolf@grasp.insa-lyon.fr
uucp-uudom somehost!wolf grasp.insa-lyon.fr!somehost!wolf
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* I'm trying to to get my mail to go into queue only mode, and it
delivers the mail interactively anyway. (Or, I'm trying to use
the "don't deliver to expensive mailer" flag, and it doesn't
delivers the mail interactively anyway.) I can see it does it:
here's the output of "sendmail -v foo@somehost" (or Mail -v or
The -v flag to sendmail (which is implied by the -v flag to
Mail and other programs in that family) tells sendmail to
watch the transaction. Since you have explicitly asked to
see what's going on, it assumes that you do not want to to
auto-queue, and turns that feature off. Remove the -v flag
and use a "tail -f" of the log instead to see what's going on.
If you are trying to use the "don't deliver to expensive mailer"
flag (mailer flag "e"), be sure you also turn on global option
"c" -- otherwise it ignores the mailer flag.
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* I'm getting "Local configuration error" messages, such as:
553 relay.domain.net config error: mail loops back to myself
554 <user@domain.net>... Local configuration error
How can I solve this problem?
You have asked mail to the domain (e.g., domain.net) to be
forwarded to a specific host (in this case, relay.domain.net)
by using an MX record, but the relay machine doesn't recognize
itself as domain.net. Add domain.net to /etc/sendmail.cw
(if you are using FEATURE(use_cw_file)) or add "Cw domain.net"
to your configuration file.
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* I want to run Sendmail version 8 on my DEC system, but you don't
have MAIL11V3 support in sendmail. How do I handle this?
Get Paul Vixie's reimplementation of the mail11 protocol
from gatekeeper.dec.com in /pub/DEC/gwtools.
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