URLs like that are NOT added by Q2A, the URL should be of the format:
example.com/confirm?c=CODE&u=USERNAME
So I guess your email provider is changing the link in some way.
If you don't want a link at all, you can change that in the language files. By default it is the file qa-include/lang/qa-lang-emails.php but the best way is to create a new file qa-lang/custom/qa-lang-emails.php with the following:
<?php
return array(
'confirm_body' => "Please click below to confirm your email address for ^site_title.\n\n^url\n\nConfirmation code: ^code\n\n Thank you,\n^site_title",
);
You need to remove the bit that says ^url and change "please click below" to something else.