Sendmail configurator Your _L_i_n_u_x computer can send and receive mail from different sources. Additionally, it can do much more than that. It can be a mail gateway between different networking technologies (UUCP and TCP/IP). It can also manage mailing lists. 11.. TTaasskkss When configuring a _L_i_n_u_x computer running sendmail you must/can do the following things: CCoonnffiigguurree bbaassiicc iinnffoorrmmaattiioonn You must minimally specify the intended purpose of your computer, mail-wise: is it a workstation or the mail server? What is the domain used for email? Etc. CCoonnffiigguurree ssppeecciiaall ((ddoommaaiinn)) rroouuttiinngg You can set up exceptions in routing. If you know a short cut to a specific site or domain, you can tell _s_e_n_d_m_a_i_l here. This is especially needed to connect _u_u_c_p sites to the Internet. CCoonnffiigguurree ccoommpplleexx ((uusseerr)) rroouuttiinngg This allows you to do mail routing based on the user and the destination domain. It is then possible to handle email to a domain one way and also perform some exceptions for few users of this domain. This feature is not a replacement for normal user aliasing, although it performs, at first sight, the same thing. MMaassqquueerraaddiinngg rruulleess You can define filters that replace the sender/domain of an email by another sender and or domain. This is handy for some broken mail gateways which send email with a bogus return address. If your Linux server is in the path, you can fix it! MMaaiill ttoo ffaaxx ggaatteewwaayy This allows your server to route email messages to your fax engine. It supports various access control rules. Mail to fax offers a universal protocol for faxing from a computer, which is easy to use and usable by any user/operating system. VViirrttuuaall eemmaaiill ddoommaaiinn A virtual email domain lets you set one independent user list, per domain, on the same server. Further, each virtual email domain may have its own administrator(s). This ability eases the management of user accounts, since each domain has its own list. Further, virtual email domains may be moved from server to server very easily to balance loads. This is a must for large organizations and ISPs. SSeettttiinngg uusseerr aalliiaass Some users may want to receive their email under different names, or you may want to set a "pseudo" user and direct the mail of this user to a real one. Good examples are postmaster, info and support. VViirrttuuaall ddoommaaiinn uusseerr aalliiaasseess Virtual domains have their own user aliases lists. GGeenneerraattee //eettcc//sseennddmmaaiill..ccff _S_e_n_d_m_a_i_l is configured using the file /etc/sendmail.cf. This file contains complex configuration commands which resembles a programming language more than a configuration file. For this reason, this file is not edited by linuxconf, but generated from scratch each time. When using this menu option, linuxconf prompts you to make sure you really want to generate this file. If you do various modifications in the sendmail configuration using Linuxconf, it will suggest that you generate a new sendmail.cf to make these configuration changes active. See the comments at the beginning of /etc/sendmail.cf to see how it is built and how manual modifications can be done (this is for experts only!). SSeettttiinngg rreejjeecctteedd sseennddeerrss This dialog lets you enter the email addresses, domains and IP numbers from which you never want to receive email. SSeettttiinngg rreellaayy ffoorr bbyy IIPP You can enter the hosts and networks for which you will accept relay mail. You generally enter your own IP networks and a few other sendmail servers and user workstations here. SSeettttiinngg rreellaayy ffoorr bbyy NNaammee Same as above, except that you enter hosts and domains here, not IP numbers. SSeettttiinngg rreellaayy ttoo hhoossttss You enter the names, IP numbers, networks, and domains for which you will accept relaying. 22.. AAlltteerrnnaattiivveess ttoo sseennddmmaaiill Sendmail is not always needed. Here are some reasons why you may want sendmail or not. +o There is already a mail server in your organization and it is reachable over the local network. You don't need sendmail. Use a mail program (user interface) which supports the SMTP and POP or IMAP protocols. +o Your computer talks _U_U_C_P with other computers (using a modem) and you want to exchange email. Use _s_e_n_d_m_a_i_l here. 33.. NNoottee ttoo nneeww IInntteerrnneett uusseerrss Most _I_n_t_e_r_n_e_t providers will set up a POP account on their server for you. You will have to connect once in a while to retrieve your mail. In this case, _s_e_n_d_m_a_i_l and _U_U_C_P shine. Ask your provider for a _U_U_C_P account also. This is especially true if you are part of a small organization. This will provide a personal account on your server for everyone in your group and your computer will forward/receive email to/from your provider. Of course, nothing beats a permanent connection to the _I_n_t_e_r_n_e_t...