The following is a Password-Protected pdf format as an example

1 - When the iphone received email from "Secure Fax2Email" service, such as (photo1-Figure 1) shows
2 - Press the attachment, this time, you can choose what apps open password-protected pdf files, such as (photo2 and photo3-Figure 2 and Figure 3) shows
3 - When you turn on password-protected pdf files, require a password, such as (photo4-Figure 4) shows
4 - the password is correct, to successfully open the pdf files, such as (photo5-Figure 5) shows

以下是以密碼保護的 pdf 格式做例子

1- 當 iphone 接收到 "傳真轉電郵 (保密版)" 服務 的電郵, 如(photo1- 圖1) 顯示
2- 按下附件, 此時, 您可以選擇用什麼 apps 開啟受密碼保護的 pdf 文件, 如(photo2 and photo3- 圖2 和 圖3) 顯示
3- 當開啟受密碼保護的 pdf 的文件時, 要求輸入密碼, 如(photo4- 圖4) 顯示
4- 密碼正確後, 就成功開啟 pdf 文件, 如(photo5- 圖5) 顯示