The Newsletter plugin sends your newsletters out-of-box using the mailing functionality provided by your WordPress blog (for tech-aware people it is named wp_mail()).
Your WordPress relies on your hosting provider for the real email delivery to the destination address. If everything works, there is nothing more you need to know. If there are problem (emails are not delivered at all or some are and other not) you should evaluate some options.
Run a test. From the Newsletter Status page run some tests and check if errors are reported. Check out delivery issue page to better understand the problem you’re facing and how to solve it.
Use your provider SMTP. You provider may provide even a mail service: you can create a dedicated mailbox for your newsletter and use the SMTP parameters they gave you with an SMTP plugin (recommended) or our SMTP integrated feature.
Choose a professional delivery service. If you need to send many emails and you need reliability, this is the better choice. They can be use as an SMTP (to be connected with an SMTP plugin) or, if supported, using one of our delivery integration add-ons which are much more performant and has the bounce retrieval integrated.
Read more about our delivery add-ons.
Delivery speed
The Newsletter plugin has an internal sophisticated engine to deliver email at fixed speed (you can set it on main Newsletter settings page). That feature saves you to hit the provider limits and the problem of dropped emails.
For example, if you need to send 1000 newsletters and you’re allowed for a speed of 200 emails per hours, Newsletter will deliver them over a 5 hours time span. The internal engine manages correctly the limits even for Automated and Autoresponder emails.
To make all that work smoothly, Newsletter needs the internal WordPress scheduler to work correctly. Sometime it has little problems you can easily solve for the benefit of the entire blog.
Read more about the internal WordPress scheduler.
Emails ending into the spam folder
If you find out that your email are classified as spam, it is a problem of the system which sends the messages (not the Newsletter plugin, is uses such systems).
There are many things you can do to fight that spam problem.