Bart,
If you are using Outlook as your email client you can set up autoresponders that are dependant on the words in the email's subject. The autoresponder can contain pdfs, jpgs, or any other type of attachment. Be sure to test the autoresponder thoroughly after you have created it. The two main steps are to create an autoresponder template and then create the rules that will trigger this autoresponder.
Create a autoreponder template:
1) Create a new email message.
2) Populate the subject field and add the body message. Attach any files you would like included.
3) Select File -> Save As
4) In the Save As window use the Save as type drop to select Outlook Template.
5) Specify a name for the file and click Save.
6) Close the message window. It will ask if you would like to save a draft of this message. Click No.
Create the autoresponder rule:
1) Select Tools -> Rules and Alerts
2) In the Rules and Alerts window select New Rule
3) In the Rules Wizard select the option for Start from a blank rule
4) Under Step 1: Select when message should be checked make sure Check messages when they arrive is selected.
5) Click Next.
6) Under Which condition(s) do you want to check? select with specific words in the subject
7) Under Step 2: Edit the rule description click the underlined text specific words
8) In the Search Text window add the words that you like to have trigger the autoresponder.
9) Click Add.
10) Click Ok.
11) In the Rules Wizard window Click Next.
12) Under What do you want to do with the message? Select reply using a specific template.
13) Under Edit the rule description click the underlined text a specific template.
14) In the Select a Reply Template window use the Look In drop down list to select User Templates in File System.
15) Select the name of the template you created. Click Open.
16) In the Rules Wizard window click Finish.
17) Test to make sure your autoresponder template is working.