Users greatly appreciate the WPO365 plugin for its effectiveness, ease of use, and strong support. The plugin reliably connects WordPress to Microsoft Exchange, facilitating smooth email sending, even from custom domains not hosted on the primary server. Users commend its thorough documentation and step-by-step guides, which make setup straightforward even for those without extensive technical knowledge. Excellent customer support, especially from Marco, enhances the user experience. However, the initial configuration can be challenging, requiring a tenant setup. Additionally, some users find the $49 fee for HTML email sending to be a drawback. Overall, users are highly satisfied, citing improved security and seamless integration as key benefits.