Sirius Pro

Simply configure your SMTP server and send email directly from WordPress site. This plugin allows you to easily send email through SMTP server and phpmailer without modifying the code and it works with most of the available themes. Just install and activate this plugin to use SMTP server and send emails in WordPress.
Read more about this plugin on <a href="https://siriuspro.pl" rel="nofollow ugc">WordPress</a> blog.

Mail SMTP

Simply configure your SMTP server and send email directly from WordPress site.

subins2000

Add multiple SMTP servers and let WordPress send email through each server one by one taking turns.
Cycle between multiple SMTP servers for sending emails through WordPress. By doing this, you can increase the number of emails you can send alltogether.
Donate
If you found this plugin helpful, please consider a donation to support me. 
http://subinsb.com/donate
Support
If you want help, you can use the WordPress Support Forum or you can seek help via comments section of http://subinsb.com/multi-smtp

Multi SMTP

Use multiple SMTP servers to send WordPress emails (wp_mail())

Mail SMTP vs Multi SMTP