mailx

The mailx utility provides a message sending and receiving facility. It has two major modes, selected by the options used: Send Mode and Receive Mode. [UP) ] ![[Option Start]]( On systems supporting the User Portability Utilities option, mail-receiving capabilities and other interactive features, Receive Mode, described below, also shall be enabled. ![[Option End]]( Receive Mode is more oriented towards interactive users. Mail can be read and sent in this interactive mode. When reading mail, mailx provides commands to facilitate saving, deleting, and responding to messages. When sending mail, mailx allows editing, reviewing, and other modification of the message as it is entered. Incoming mail shall be stored in one or more unspecified locations for each user, collectively called the system mailbox for that user. When mailx is invoked in Receive Mode, the system mailbox shall be the default place to find new mail. As messages are read, they shall be marked to be moved to a secondary file for storage, unless specific action is taken. This secondary file is called the mbox and is normally located in the directory referred to by the HOME environment variable (see MBOX in the ENVIRONMENT VARIABLES section for a description of this file). Messages shall remain in this file until explicitly removed. When the -f option is used to read mail messages from secondary files, messages shall be retained in those files unless specifically removed. All three of these locations-system mailbox, mbox , and secondary file-are referred to in this section as simply "mailboxes", unless more specific identification is required. ![[Option End]]( The following options shall be supported. (Only the -s subject option shall be required on all systems. The other options are required only on systems supporting the User Portability Utilities option.) [UP) ] ![[Option Start]]( Test for the presence of mail in the system mailbox. The mailx utility shall write nothing and exit with a successful return code if there is mail to read. ![[Option End]]( [UP) ] ![[Option Start]]( Read messages from the file named by the file operand instead of the system mailbox. (See also folder .) If no file operand is specified, read messages from mbox instead of the system mailbox. ![[Option End]]( [UP) ] ![[Option Start]]( Ignore interrupts. (See also ignore .) ![[Option End]]( [UP) ] ![[Option Start]]( Do not initialize from the system default start-up file. See the EXTENDED DESCRIPTION section. ![[Option End]]( Addressee of message. When -n is specified and no user start-up files are accessed (see the EXTENDED DESCRIPTION section), the user or application shall ensure this is an address to pass to the mail delivery system. Any system or user start-up files may enable aliases (see alias under Commands in mailx ) that may modify the form of address before it is passed to the mail delivery system. [UP) ] ![[Option Start]]( Some of the functionality described in this section shall be provided on implementations that support the User Portability Utilities option as described in the text, and is not further shaded for this option. ![[Option End]]( Provide a default value for the internationalization variables that are unset or null. (See XBD Internationalization Variables for the precedence of internationalization variables used to determine the values of locale categories.) If set to a non-empty string value, override the values of all the other internationalization variables. Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi-byte characters in arguments and input files) and the handling of case-insensitive address and header-field comparisons. This variable may determine the format and contents of the date and time strings written by mailx . This volume of POSIX.1-2017 specifies the effects of this variable only for systems supporting the User Portability Utilities option. Dete