Hi to all again and thanks for the great help,

Considering the amount of help i'm receiving i should clear things up.
Firstly about me:
1. I can get a script to work (or apparently do so), but in no way will it be efficient or secure.
Although I may not be a beginner I am far from being experienced.

About the script:
1. This script is (toghether with others) going to be used for managing a newsletter: people will be able to subscribe and remove themselves and only I will be able to send them the newsletter.
2. The script is going to be in php with the exclusion of the bulk mail section which is going to be in perl.
3. I am on a low cost server.

The script is going to be divided in two parts
4. An admin section which is going to be protected by .htaccess (of which this perl script is going to be part)
5. A public script which can be accessed by everybody

With these premises let me update you with the situation.
1. I am now testing the script having removed as many print MAIL as possible.
2. Unluckily moving the open MAIL and close MAIL outside the iteration does not seem to work. Maybe I'm doing something wrong and somebody ccould suggest something.
3. I don't have a clue how to use CGI.
4. I am equally clueless about security issues.
(maybe somebody could help me here)
5. For Ovid:
$value =~ s/%0D%0A/|/g;
I am not sure what security implications this has, I've always used it in order not to loose line breaks in the textarea, maybe you now of better ways.

I am now testing: I will be posting results and the "modified" script as soon as I've finished.

Again thanks to all for your help.

ciao,
Adrien