Communication Error [334] – Send a Test Email

When sending email, the message fails and I get the following status:

Communication Error [334] – make sure the Envelope From email is the same account used to create the Client ID.

I have checked that the Envelope-From Email Address matches the Google account email address that was used to create the client ID and that I am currently signed into that account only, which has no security messages.

Please can you help me resolve this?

Here are the diagnostic test results:

OS: Windows NT DDSWEB01 6.2 build 9200 (Unknow Windows version Standard Edition) i586
PHP: WINNT 5.3.28 English_United Kingdom.1252
PHP Dependencies: iconv=Yes, spl_autoload=Yes, openssl=Yes, sockets=No, allow_url_fopen=Yes, mcrypt=Yes, zlib_encode=Yes
WordPress: 4.5.3 en_US UTF-8
WordPress Theme: Point
WordPress Plugins: All In One SEO Pack, amr shortcode any widget, Column Shortcodes, Contact Form 7, Google Tag Manager for WordPress, Enable Media Replace, Flamingo, Flickr Badges Widget, Flickr Justified Gallery, Jetpack by WordPress.com, Links With Icons Widget, MailChimp Widget, One-Click Child Theme, Postman SMTP, Really Simple CAPTCHA, Redirection, Regenerate Thumbnails, Shortcodes Ultimate, Simple Share Buttons Adder, Stop Spam Comments, Compress JPEG & PNG images, UpdraftPlus - Backup/Restore, Wordfence Security, WordPress Importer, Yoast SEO
WordPress wp_mail Filter(s): wp_staticize_emoji_for_email
WordPress phpmailer_init Action(s): wpcf7_phpmailer_init
Postman: 1.7.2
Postman Sender Domain (Envelope|Message): thepartsalliance.com | thepartsalliance.com
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Active Transport: SMTP (smtp:tls:oauth2://smtp.gmail.com:587)
Postman Active Transport Status (Ready|Connected): Yes | Yes
Postman Deliveries (Success|Fail): 155 | 44
Postman File Locking (Enabled|Temp Dir): No | /tmp

https://ww.wp.xz.cn/plugins/postman-smtp/