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quietly, patiently, for you to do something reasonable like trying to upgrade the project to a newer version of PHP.
And of all my favorite deprecated functions to run into when evaluating old projects for a conversion to the newest version of PHP, there’s nothing quite like “magic quotes.”
When this directive is enabled it adds slashes to quotes (and a few other things, as mentioned above) in the assumption that it’s helpfully preventing a possible SQL injection attack.
OK, for the sake of argument, let’s assume somehow that a string is passed in that DID contain an SQL injection attempt, and that magic quotes has saved the day.
In other words: PHPMailer doesn’t depend on magic quotes, and this error being thrown into the logs is because they did their jobs correctly.