Registration Emails are marked as spam

Hello,

currently I have the following problem:

For some weeks, all emails that contain the activation link for new users are no longer delivered.

The support of my provider "siteground.com" wrote me today that there is a problem with the registration script.
I should contact the developer of the script.

Currently all automatic outgoing emails are classified as spam during registration and blocked.

Joomla and CB are up to date.
CB Registration uses the Joomla settings for email delivery.
Joomla email is sent via SMTP.

If I open the user list and click on "Send activation link again", then the email is delivered.

Can someone help me solve the problem?

Greetings
Joerg.

Currently all automatic outgoing emails are classified as spam during registration and blocked.

CB has no control over this. Your domain is being classified as spam by email providers (e.g. GMail, Yahoo, etc..). Everyone should be changing the emails to be less generic so they are less likely to appear as spam. You can change them in CB > Configuration > Registration. While the defaults will work fine you have to keep in mind there's millions of CB sites with many using the defaults, which to a provider like GMail will seam like spam when thousands of sites are sending near identical emails.