How to password protect multi PDF files while sending automatically?

You can use A-PDF AutoMail (free download here) to auto send mails to multiple recipients, and the mail addresses can be auto extracted from PDF database.

Further more, you can choose mail server as MS Outlook or SMTP Internet Server, and set security on PDF files which to be sent out.

The tutorial below explains how to send password protected PDF files to multiple recipients automatically:

1. Free download and install A-PDF Automail, Operate Pdfam.exe, the first step is to add PDF files as datasource and attachments:

2. Select a Rule for extracting data from PDF datasource as mail information: click the icon for "Add rule", you will see an interface as follows to edit a new rule based on your PDF template:
<1>Choose a PDF document as sample to extract content;

<2>Right click on the selected content, choose a tag mode for inserting, such as "Mail to", "CC", "BCC", "Subject" or "Macro Tag" as message content, and you can also click "Macro" in "Mail settings" to choose metadata as mail information;

<3>Define a name for Rule, and then click "Save" for storing the rule.

3. Click "Settings->Security" to set Security Method for protecting PDF attachments, and you can also set for Email Server in "Email Settings": "Use current email application (i.e. Outlook Winmail and etc…)" or "Use Internet E-mail Server (SMTP)":
4. Click "Email" to start to e-mail with PDF attachments, then the mail results will be listed in log viewer box as follows: