Maybe this helps narrow it down for the LimeSurvey devs, emails get sent for accounts I create with the non-initial user. I.E. creating new users as a superadmin but not as the initial user. When I create users as that initial superadmin account, emails fail to send.

EDIT: Scratch that, now email is sending fine as the initial superadmin account. No idea what I changed, if anything, for it to work. Only failed the very first time I ever sent an email, has worked every time since.

Please always let us know which email method you set at global settings -> email.

When using SMTP emailing please enable error logging and post errors here.

If you can safely reproduce the issue please file a bug report.

I use SMTP which worked very well before.

And there are no further details available when enabling SMTP error output?

Haven't used the SMTP error output yet. Have to see how to activate this first and them make some new tests.

Just saw that this is a feature of the GUI, thought I have to tinker with the config file.

It was already set to "on error". So there were no further errors reported.

But, I think I found at least my problem: Security was set to TLS and when I switched to SSL the email got sent.