PHP Notice – problem with ajax call

If you previously set a campaign id or tag (for me the tag in the admin has the name “campaign-id”) and afterwards removed it, the key is still set in the database. thus on line 153 in wp-mail.php there will be a notice “undefined index” because there are no tags because the field in the backend is empty.

this causes problems – in our case an ajax resonse after the form/email sent – so please also check for not empty on the value.

thank you