One common issue while sending emails is when they keep bouncing back. The non-delivery report mentions the error as the presence of an illegal attachment. This ...

Portable Document Format or PDF files are documents that have been converted from printable source material, such as Microsoft Word or Excel files. PDF documents may be color or grayscale. PDF files ...

Usually, there are dedicated applications to view different types of files. However, if you are looking for a viewer that lets you view files of multiple types, you have landed on the correct article.