Comments and questions on this FAQ should be directed to sendmail+faq@sendmail.org.
General questions about sendmail should be directed to sendmail-questions@sendmail.org.
Bug reports should be directed to sendmail-bugs@sendmail.org.

If you post a message to comp.mail.sendmail and send it to one of the above addresses, please clearly indicate so at the top of your message.

Top 5 - the most frequently asked questions about sendmail

1. Local config error: see 4.5
2. Relaying denied: see 3.27
3. Directory permissions: see 3.33
4. Virtual hosting: see 3.7 & 3.28
5. POP / IMAP: see 4.19

Table of Contents

• 1. COPYRIGHT NOTICE / REDISTRIBUTION REQUIREMENTS
• 2. INTRODUCTION / MISCELLANEOUS
  • 2.1 What is this newsgroup?
  • 2.2 What is the scope of this FAQ?
  • 2.3 Where can I find the latest version of this FAQ?
  • 2.4 How do I access comp.mail.sendmail by email?
  • 2.5 Where can I ask email-related DNS questions?
  • 2.6 How can I subscribe to these newsgroups?
  • 2.7 Which version of sendmail should I run?
  • 2.8 What is the latest release of sendmail?
  • 2.9 Where can I find it?
  • 2.10 What are the differences between Version 8 and other versions?
  • 2.11 What's the best platform for running sendmail?
  • 2.12 What is BIND and where can I get the latest version?
  • 2.13 What is smrsh and where can I get it?
  • 2.14 What is smap and where can I get it?
  • 2.15 What is TCP-Wrappers and where can I get it?
  • 2.16 Why won't db 1.85 build on my machine?
  • 2.17 What is makemap and where can I get it?
• 3. VERSION 8 SPECIFIC ISSUES
  • 3.1 How do I make all my addresses appear to be from a single host?
  • 3.2 How do I rewrite my "From:" lines to read ``First_Last@My.Domain'' or ``Different_Name@My.Domain''?
  • 3.3 But what about fully-qualified addresses, such as those from Pine or FEATURE(always_add_domain)?
  • 3.4 So what was the user database feature intended for?
  • 3.5 Why the hostility toward using full names for email addresses?
  • 3.6 deprecated
  • 3.7 How do I manage several (virtual) domains?
  • 3.8 There are four UUCP mailers listed in the configuration files. Which one should I use?
  • 3.9 How do I fix "undefined symbol inet_aton" and "undefined symbol _strerror" messages?
  • 3.10 How do I solve "collect: I/O error on connection" or "reply: read error from host.name" errors?
  • 3.11 Why can't my users forward their mail to a program?
  • 3.12 Why do connections to the SMTP port take such a long time?
  • 3.13 Why do I get "unknown mailer error 5 -- mail: options MUST PRECEDE recipients" errors?
  • 3.14 Why does version 8 sendmail panic my SunOS box?
  • 3.15 Why does the Unix From line get mysteriously munged when I send to an alias?
  • 3.16 Why doesn't MASQUERADE_AS (or the user database) work for envelope addresses as well as header addresses?
  • 3.17 How do I run version 8 sendmail and support the MAIL11V3 protocol?
  • 3.18 Why do messages disappear from my queue unsent?
  • 3.19 When is sendmail going to support RFC 2047 MIME header encoding?
  • 3.20 Why can't I get mail to some places, but instead always get the error "reply: read error from name.of.remote.host"?
  • 3.21 Why doesn't "FEATURE(xxx)" work?
  • 3.22 How do I configure sendmail not to use DNS?
  • 3.23 How do I get all my queued mail delivered to my Unix box from my ISP?
  • 3.24 Why do I get the error message unable to write /etc/mail/sendmail.pid?
  • 3.25 Why can't I compile sendmail with Berkeley DB 2.X?
  • 3.26 What operating systems has Berkeley sendmail been ported to?
  • 3.27 How do I prevent Relaying Denied errors for my clients?
  • 3.28 Why isn't virtual hosting working, even after I added a Kvirtuser line to sendmail.cf ?
  • 3.29 How can I add a header specifying the actual recipient when having multiple users in a virtual domain go to a single mailbox?
  • 3.30 What do I do when Build fails because groff was not found?
  • 3.31 What does "class hash not available" mean?
  • 3.32 How do I configure majordomo with sendmail 8.9 without relaxing the DontBlameSendmail option?
  • 3.33 How do I configure my system in general with sendmail 8.9?
  • 3.34 What does "foo not available for sendmail programs" mean?
  • 3.35 How do I add a footer/signature to all (outgoing) e-mail messages?
  • 3.36 What does "Cannot open hash database ... Invalid argument" mean?
  • 3.37 What does "parse error before `NDBM'" mean?
  • 3.38 What does "may be forged" mean?
  • 3.39 How do I send using an alternate port?
  • 3.40 Why can't I use BerkeleyDB 4.1.x?
  • 3.41 How do I use CIDR notation in the access map (or other places)?
  • 3.42 Why isn't CIDR notation directly supported by sendmail?
  • 3.43 What does "Need to recompile with -DNEWDB for hash support" mean?
  • 3.44 I disabled sendmail on some machines which don't receive mail, but since upgrading to 8.12 they can't send mail either; why?
• 4. GENERAL SENDMAIL ISSUES
  • 4.1 Should I use a wildcard MX for my domain?
  • 4.2 How can I set up an auto-responder?
  • 4.3 How can I get sendmail to deliver local mail to $HOME/.mail instead of into /usr/spool/mail (or /usr/mail)?
  • 4.4 Why does it deliver the mail interactively when I'm trying to get it to go into queue only mode?
  • 4.5 How can I solve "MX list for hostname points back to hostname" and "config error: mail loops back to myself" messages?
  • 4.6 Why does my sendmail process sometimes hang when connecting over a SLIP/PPP link?
  • 4.7 How can I summarize the statistics generated by sendmail in the syslog?
  • 4.8 How can I check my sendmail.cf to ensure that it's re-writing addresses correctly?
  • 4.9 What is procmail, and where can I get it?
  • 4.10 How can I solve "cannot alias non-local names" errors?
  • 4.11 Is sendmail Year 2000 (Y2K) compliant?
  • 4.12 How can I batch remote mail to be sent using my ISP while delivering local mail immediately?
  • 4.13 What does "unknown mailer error 1" mean?
  • 4.14 How do I queue mail for another domain?
  • 4.15 How do I create attachments with sendmail?
  • 4.16 How do I find sendmail's version number?
  • 4.17 How do I handle user names with upper-case characters?
  • 4.18 What does "NOQUEUE: Null connection from ..." mean?
  • 4.19 How do I configure sendmail for POP/IMAP/... ?
  • 4.20 How can I automatically copy messages based on sender or recipient addresses?
  • 4.21 How can I send mail to all users?
  • 4.22 Why can't I receive external mail?
  • 4.23 How do I restrict attachments with sendmail?
  • 4.24 Can I get sendmail to verify an entire e-mail address instead of just the domain?
• 5. VENDOR/OS SPECIFIC SENDMAIL ISSUES
  • 5.1 Sun Microsystems SunOS/Solaris 1.x/2.x
    • 5.1.1 How can I solve "line 273: replacement $3 out of bounds" errors?
    • 5.1.2 How can I solve "line 445: bad ruleset 96 (50 max)" errors?
    • 5.1.3 Why does version 8 sendmail (< 8.7.5) sometimes hang under Solaris 2.5?
    • 5.1.4 Why can't I use SunOS/Solaris to get email to certain large sites?
    • 5.1.5 Why do I have trouble compiling on Solaris?
    • 5.1.6 How does 8.X compare to 8.X+Sun?
  • 5.2 IBM AIX
    • 5.2.1 The system resource controller always reports sendmail as "inoperative". What's wrong?
    • 5.2.2 Why can't I use AIX to get email to some sites?
    • 5.2.3 Why can't I get sendmail 8.7.1 to use MX records with AIX 3.2.5?
  • 5.3 Linux
    • 5.3.1 Red Hat
      • 5.3.1.1 Why do I have so many sendmail problems after configuring sendmail with linuxconf?
      • 5.3.1.2 I built sendmail.cf from sendmail.mc and it works until the next reboot of the machine. What is going on?
      • 5.3.1.3 Why can't I receive mail with Red Hat 7.1 and later?
    • 5.3.2 SuSE
      • 5.3.2.1 Where is the sendmail.mc file on SuSE Linux?
• 6. ADDITIONAL INFORMATION SOURCES (RFC 1807 bibliography format)
  • 6.1 Reference material devoted exclusively to sendmail
  • 6.2 Reference material with chapters or sections on sendmail
  • 6.3 Reference material on subjects related to sendmail
  • 6.4 World-wide web index pages on sendmail
  • 6.5 World-wide web index pages Internet email in general
  • 6.6 Online tutorials for sendmail
  • 6.7 Online archives of mailing lists and Usenet newsgroups, relating to Internet email
• 7. THANKS!