- If you have C language developing experience, look at the conf.c file. Observe how sendmail initializes its default values and how it accommodates many operating systems. Read the code in the checkcompat() function.
- Look in the contrib directory. Determine whether any of the contributed software or documents are of value to you or your site.
- For a historical understanding of the philosophy behind sendmail, read the document doc/usenix/usenix.ps. If you have access to the Internet, get and read the RFCs mentioned in the Preface.