NAME:
  mailmsg
 PURPOSE:   (one line only)
  Send an email message
 DESCRIPTION:
 CATEGORY:
  Utility
 CALLING SEQUENCE:
  mailmsg,toaddr,subject,text
 INPUTS:
  toaddr - string, email address to send to.
  subject - string, subject line for message
  text - string (array or scalar), this is the body of the message to
           be sent.  Each entry in the string array is sent as a separate
           line.  No line processing is done but the line is checked to
           make sure it won't trip special processing by the mail program.
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  CCADDR - string (array or scalar) of additional addresses to send to.
             default = no Cc: recipients
  BCCADDR - string (array or scalar) of additional addresses to send to
              with blind carbon copies (bcc:).
             default = no Bcc: recipients
  REPLYTO - string (array or scalar) of address(es) to be set for any
              reply.
  MAILCLIENT - name of external mail program, default='mail'
 OUTPUTS:
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
  This program will create a temporary file named 'idl_tmpmail.txt' in the
    current directory.  It will be deleted when done but the program must
    have write permission to succeed.
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Lowell Observatory, 2004/11/01
  2016/11/30, MWB, added BCCADDR keyword
  2016/12/05, MWB, added REPLYTO keyword