[D6] Email Flooding Filter

I've tested this and its working properly. Perhaps you should be using the regex in valid_email_address().

You should add some more information to this issue (Drupal version, project page, repo).
Add some info on how to use the module on your project page, could be useful for people not familiar with drupal 6.

Also you have some code formatting issues:

It appears you are working in the "master" branch in git. You should really be working in a version specific branch. The most direct documentation on this is Moving from a master branch to a version branch. For additional resources please see the documentation about release naming conventions and creating a branch in git.
Review of the master branch:

README.txt is missing, see the guidelines for in-project documentation.
Remove "version" from the info file, it will be added by drupal.org packaging automatically.
Remove "project" from the info file, it will be added by drupal.org packaging automatically.
Drupal Code Sniffer has found some code style issues (please check the Drupal coding standards). (http://ventral.org/pareview/httpgitdrupalorgsandboxsubhransu1509890git)

@geertvd, please don't paste these large ugly reports in here. rather use an attachment or direct link to it.
Please edit your last comment and short it, thanks ;)

Functionality of this module is already implemented in SpamSpan module http://drupal.org/project/spamspan

Please view this module and provide - what is the difference between your module and this one.

If no difference - why create duplicated modules - this will only complicate for users who are not very good familiar with Drupal

Unfortunately I have to agree with Drupaldriven,

it seems that your module is pretty much duplicating the functionality of spamspam.

To prevent duplication I'll close this issue (reopen when disagree)

Please consider joining forces with the maintainers of spamspam and come back with a new module another time for application

Sorry
regards