Skip to main content

Configuration Tuning To Send Email More Reliably

By March 21, 2016November 2nd, 2017No Comments

It’s important to know how emails are delivered, since you’re definitively sending emails! To make complex things simple, every email you send is delivered to a sending server which in turns send the email to a receiving server, the one from which your contact will get the message. Your WordPress blog relies on the server it is running to send emails using the only method provided by PHP (the programming language used to code WordPress). WordPress does not know how much reliable is the sending server and most of the time it receive a success message while the email is actually not sent at all.

Integration With SMTP Plugins (like Postman)

The Newsletter Plugin, since the version 4.1.1, uses WordPress to send emails sacrificing some nice features (that can be anyway restored). This almost breaking change has been made for a good reason: bloggers have many plugins that can be used to force WordPress to use alternative and more reliable methods to send emails. Probably the most famous is Postman SMTP. Using WordPress as first choice to send emails lets bloggers to control how each email send by their site is delivered.

Tested with: Postman, WP Mail SMTP, Easy WP SMTP, Easy SMTP Mail, WP Mail Bank (but probably works with any other).


The Newsletter Plugin lets to have a textual version of newsletters, but using WordPress to send email that textual part cannot be easily managed. So it is dropped. In the main configuration panel it’s possible to restore the old behavior, letting Newsletter to manage in its own the mail delivery. Basically Newsletter acts as WordPress but does not interact with SMTP plugins like Postman. Hence, if you’re using those kind of plugins you can:

  1. let Newsletter to send emails using WordPress (and so using the SMTP plugin you installed): recommended
  2. configure Newsletter to manage its own the sending and eventually configure the SMTP panel to mimic the configuration of the SMTP plugin (not all configurations/options could be available)

Newsletter Skips WordPress When…

Anyway, Newsletter must send on its own when:

  1. you configure a SMTP directly in Newsletter and enable it instaed of using an SMTP plugin
  2. you are using one of our integration extensions (for example with Sendgrid, Mailjet and so on)

When Newsletter sends on its own all the features are enabled, like the textual part, selection of the content encoding, reply to and return path headers and few other.

About Delivery Speed And Throttling

Delivery speed, as you can configure it on main setting, should not be affected but it depends on the SMTP plugin you’re using and the possible overhead or eventually better performances it provides.

The throttling is a technique to send emails slowly enough to not get over the provider allowed mails per hour rate. Plugin applying this technique, like Mailer, are perfectly compatible with Newsletter since the latter anyway respect the delivery speed set on its configuration.


Take a look at our premium extensions!