このエラーメッセージに関する原因と対処に関して説明します。
エラーメッセージ(英語)：
phpmailer not working
対処
関連リンク
PHPMailer not working in my server - Stack Overflow
https://stackoverflow.com/questions/34084449/phpmailer-not-working-in-my-server
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https://stackoverflow.com/questions/48208285/phpmailer-not-running-with-xampp-on-windows10
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https://stackoverflow.com/questions/34360465/phpmailer-not-working-consistently
php - PHPMailer: SMTP Error: Could not connect to SMTP host - Stack ...
https://stackoverflow.com/questions/3477766/phpmailer-smtp-error-could-not-connect-to-smtp-host/3640・・・
PHPMailer can't send via postfix - Stack Overflow
https://stackoverflow.com/questions/39927267/phpmailer-cant-send-via-postfix?rq=1
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Highest Voted 'phpmailer' Questions - Page 3 - Stack Overflow
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https://stackoverflow.com/questions/tagged/phpmailer?sort=newest&page=3
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Highest Voted 'phpmailer' Questions - Page 3 - Stack Overflow
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