Magento 2 SMTP extension supports to do basic assistance functions such as configure SMTP server & prevent your email from heading straight to the receivers’ junk/spam mail box.
With SMTP extension for Magento 2, you can choose to send your emails from a reliable server hosting or your own custom server to minimize the possibility of your promotional emails getting to the spamming box as well as some other helpful features.
Explore Other Best Magento 2 Extensions
Community Edition: 2.0.x, 2.1.x, 2.2.x, 2.3.x, 2.4.x
Enterprise Edition: 2.0.x, 2.1.x, 2.2.x, 2.3.x, 2.4.x