Undefined variable and index errors

Thanks for the plugin – just giving it a try as I think it could be really useful. I’m a newb but I’m getting the following errors in case you wanted to take a look:-

[25-Jul-2016 15:02:59 UTC] PHP Notice: Undefined index: in /volume1/web/wordpress/wp-content/plugins/save-contact-form-7/save-contact-form-7.php on line 891
[25-Jul-2016 15:14:08 UTC] PHP Notice: Undefined variable: export in /volume1/web/wordpress/wp-content/plugins/save-contact-form-7/save-contact-form-7.php on line 324
[25-Jul-2016 15:14:08 UTC] PHP Notice: Undefined variable: dt_column_target in /volume1/web/wordpress/wp-content/plugins/save-contact-form-7/save-contact-form-7.php on line 380

The first one seems to go away by making the line conditional on a check for a null fieldname (I don’t have a file upload field on my form):

if ($fieldname != “”) {
$uploaded_file_info = pathinfo($submited[‘posted_data’][$fieldname]); //uploaded file info like basename,extension etc
}

https://ww.wp.xz.cn/plugins/save-contact-form-7/