Empty or non-existent Regular Expressions and files

From ASSPSMTP

Regular Expression lines and files should never be empty or non-existent. In Regular Expression processing, this will cause a "0 to 0" match. If you compare nothing to nothing - you have a match. The following are different examples of "0 to 0" matches that should never be in a Regular Expression line or file:

• Never specify an empty or non-existent Regular Expression file in ASSP's configuration.
• Never have blank lines with carraige returns in a Regular Expression file in ASSP's configuration. However, it is OK to have a blank line at the end of a Regular Expression file - so long as there is no carraige return.
• Never have repetitive pipes ( || ) in a Regular Expression. This is processed the same as a blank line with a carraige return.
• Never have a trailing pipe ( | ) at the end of a Regular Expression. This is processed the same as a blank line with a carraige return.