Why some times iZip does not open my email attachment?

[comcsoft]

iZip supports to open in many files types, including: zip, gz, rar, pdf, doc, xls,ppt,txt and video, and audio files from your email. Just long press the email attachment and pick iZip from the App list.

Due to a known issue on iOS Email App, some files with long names or extra "." in the file names could fail to be opened in other Apps. This will happen not only on iZip but any other Apps. We have no solution for this problem right now. Please use shorter or simple names for your files when sending them as email attachments.