I have migrated my website to a new host today and am having a problem with the Newsletter plugin.
I am seeing an error message “The WP scheduler doesn’t seem to be running correctly for Newsletter. Read this page to solve the problem.” WP Cron is set-up correctly and test emails are sending and received correctly.
On the Newsletter Status page under “Your Server” the details shown are still those for my old server. However I am accessing the site on the new server.
Could this issue just be a DNS problem that will go after DNS propagation?
No, it’s a DNS problem. Your new server is still resolving your domain to the old server. Forget the status panel for a couple of days and probably everything will be fine after 48 hours. If the problem persists you should ask the provider is the server is using an update DNS server.