It may happen to have the test messages from the Status panel and the regular activation and welcome messages correctly delivered but the test newsletters not. Why?
That problem is mostly connected to filters or limits at the provider level.
First a short tech note: Newsletter sends ALL messages using the same method. Being the message a newsletter or a service message there are no differences on the delivery method. What changes is the email content, of course.
To quickly debug this issue, you should create a simple newsletter starting from the “blank” template. Use a generic subject and few line of content without images and links.
Test that simple newsletter: if it is delivered there is a filter on your provider mailing system. Contact them and ask details.
Which are the possible contents that could trigger the filter?
- the use of images
- the use of images from a domain different than yours
- the use of particular words (we have not a list, the provider should be of help on that)
- the return path and/or reply to address (see Newsletter main settings) and not good for your provider
- the sender address are not good (for example if it is not a real mailbox and/or not using the site domain)
- some kind of links
As you understand all those contents could be regular parts of a newsletter hence a filter can create serious issues and. what’s worse, they can be totally impredictable (a newsletter work another one not).
A different approach is to use an external delivery service or via our integrations or just using their WP plugins (if availbale) or an SMTP plugin with their SMTP settings. Remeber to ask your provider, if you decide for an SMTP approach, if you’re allowed to connect to and external SMTP server.