You already have some specific answers. These are some additional observations:

  1. ...wihout (sic) using external module
    and
  2. ...where it's not possible to install a module for the purpose.

As a general rule (though not in this case), the phrase in 1 is justified only when the writer is interested in reinventing the wheel for educational purposes or cannot compile the module in question for the OS in use.

The clause in 2 is highly unlikely to be true (in terms of desired functionality) on any server for which the writer has the necessary permissions to install a script.

The reading suggested by moritz provides detail and in the Monastery's Tutorials section, you may find Installing Modules on a Web Server relevant, along with others in Installing Modules.

In reply to Re: Sending E-mail attachment wihout using external module by ww
in thread Sending E-mail attachment wihout using external module by DreamT

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