Lost my html content are for setting up a campain

could the code in the .htaccess file being changed stop me from being able to write out content in my emails? my server support was working on something and changed the .htaccess content, up till they did this my emailer was working great, I had just sent out a couple emails before it stopped working,
question is there a limitation on the PHPList program that is downloaded and loaded on our own servers?