sendmail;;
* Quoted aliases and quoted addresses are not supported: lines that
contain a `"` symbol are ignored.
-* Line continuations are not supported: lines that start with
- whitespace characters, or end with a `\` symbol are ignored.
+* Redirection to a file (`/path/name`) or pipe (`|command`) is not
+ supported.
+* File inclusion (`:include: /path/name`) is not supported.
* Warnings are printed on the standard error output for any
explicitly unsupported constructs, and any other lines that are not
recognized by the parser.