Sendmail basic information Introduction For most system, this is probably the only form you will have to fill to get email going. This configuration generally differentiate email servers from "client" workstations. 11.. PPrreesseenntt yyoouurr ssyysstteemm aass Even if email may come from different machines in your organization, you may want to hide this fact and present email as if they were from a single machine or domain. This field is normally used in most setup and simply contain your official domain name. 22.. AAcccceepptt eemmaaiill ffoorr ""yyoouurr ddoommaaiinn"" If you are configuring the main server of an organisation, you must check this field on. Normally, a sendmail server will accept only email sent to its fully qualified host name. If this is the main server, it will generally receive email addressed to the domain, not the server name. Checking this box allow the server to accept both as equivalent. For example, if your domain is foo.com and your server is mail.foo.com, then mail to joe@foo.com and mail to joe@mail.foo.com will be accepted and stored locally on this server (If user joe do exist). 33.. mmaaiill sseerrvveerr In most organization, there is one machine which store email for all users, even if the email may originated from different machines. _U_n_i_x machines are multiuser. It is possible for a user to send email to another user on this machine. The default behavior is to store the message in the mail folder of the user on this machine. This is often inappropriate. _U_n_i_x machines are not only multiuser, but network oriented. This user (the recipient) may very well have accounts on many machines on the network (often on all machines) and may elect to read his email messages on another machine. Having his email messages spread-ed on all machines on the net is not useful. You just specify the fully qualified name of the mail server of the organization and all email messages will be forward to it. 44.. MMaaiill ggaatteewwaayy Most machine on a net lack the connectivity to forward email properly. You can specify the name of a machine which knows better. In many organization, this is often the same as the mail server. Unlike the mail server, the mail gateway may be reached by different mailer transport/protocol such as ESMTP and UUCP. 55.. MMaaiill ggaatteewwaayy pprroottooccooll You must specify how to reach the mail gateway. If you choose ESMTP, then you must specify a fully qualified name for the mail gateway. If you specify UUCP, then you must specify a uucp name for the mail gateway. 66.. FFeeaattuurreess 66..11.. NNoo bbaattcchhiinngg ffoorr uuuuccpp mmaaiill 66..22.. MMaaxx ssiizzee ffoorr uuuuccpp mmeessssaaggeess UUCP message may be limited. Larger message will be dropped. This is useful for slow modem link. Setting the maximum to 0 will disable this feature (no limit). 66..33.. DDeelliivveerr llooccaallllyy ttoo uusseerrss Enter the name of users for whom you want to defeat the mail host definition. Messages will always be stored locally for those users. This feature is normally used for administrative pseudo user (root for one). 66..44.. NNoo mmaassqquueerraaddee ffrroomm uusseerrss You may want to defeat the "present your system as" field for some users. One is root. This allow the recipient to differentiate easily from which system (which root ?) the message originates. 66..55.. SSppeecciiaall rroouuttiinngg ddaattaabbaassee eennaabblleedd Check that if you intended to use special domain routing. Unfortunatly, linuxconf can't probe the sendmail distribution you have to know if this sendmail does support special routing database and which format is supported. These are compiled time option for sendmail and no sendmail command line option allows the retrieval of those compiled time features. 66..66.. SSppeecciiaall rroouuttiinngg ddaattaabbaassee ffoorrmmaatt _S_e_n_d_m_a_i_l may use several format for some of its database. It generally default to the dbm format. Please note that that some _S_e_n_d_m_a_i_l only support one format (dbm). This is a compile time option. 66..77.. LLooccaall ddeelliivveerryy aaggeenntt Different utilities are used to manage email sent to local user. Those utilities provide various extension allowing the user to tailor the delivery. procmail for one supports fancy filtering. Some people use procmail to split incoming messages in several inboxes based on various criterion. You can leave this field empty and linuxconf will locate the proper utility available on your system. 66..88.. DDoonn''tt ttrryy ttoo ddeelliivveerr iimmmmeeddiiaattllyy This feature is intended for people without a continuous internet connectivity. This tells sendmail to save the mail without further checking. Later on, one can trigger the delivery of the mail. This is usually done by specifying a post connection command (see linuxconf ppp dialout support) like "/usr/sbin/sendmail -q". This force sendmail to process its queue and deliver the messages. 66..99.. PPrroocceessss qquueeuuee eevveerryy ((mmiinnuutteess)) Once in a while sendmail wakes up and tries to deliver the email it was not able to deliver at first previously. You can see the content of the queue with the command mailq without arguments. People without continuous internet connectivity may want to play here. Setting the delay to 0 disable the feature. If your connectivity is _o_n _d_e_m_a_n_d, you may want to put a larger number such as 30 minutes. When sendmail will wake up, it will/should trigger a connection. Those who disable the feature may want to control sendmail by hand (or with a cron job) with the command /usr/sbin/sendmail -q 66..1100.. SSuuppppoorrttss bboogguuss mmaaiill cclliieenntt((HHEELLOO)) Some mail clients which use SMTP to send email are broken. They generate bad HELO sequences. Sendmail normally rejects such connections. With this option, sendmail is tolerant. It still accepts valid connection. 77.. _S_e_n_d_m_a_i_l aanndd tthhee _D_N_S _S_e_n_d_m_a_i_l makes heavy use of the _D_N_S. Machine with no _I_n_t_e_r_n_e_t connectivity at all (even behind a firewall) may want to deactivate DNS usage. On the other end, machines with normal _D_N_S connectivity should force _D_N_S usage. 88.. AAlliiaasseess ffoorr yyoouurr ssyysstteemm Email message which match the fully qualified name of your machine will be accept by _S_e_n_d_m_a_i_l. Other will be either bounce back or forward. You may want to accept email messages for different domains. Once situation is when you register with an Internet provider and he gives you one sub-domain of his own. You start using it. Later, you request your own domain. You still want to accept the old one, because many peoples knows you with this address. You are allowed to enter as many line as you need here. Use the Add button to grow the dialog.