Understanding why an email address is blocked

There will unfortunately always be the risk of emails bouncing and becoming blocked in any system. Here is an article that describes the differentiation between these:

Understanding Bounced / Blocked emails

Blocked emails are no longer available for sending emails, therefore it is recommended that you actively monitor blocked emails in the EnrolNow system. You can do this by going to the children module and ensuring that the child view is set to All Children, then, apply a filter on the email field to show all children where email "is blocked", as shown here:

Any emails shown in this view will not be able to be sent emails. A blocked reason should be shown in the last column displayed. These reasons will indicate the potential fix eg.

5.1.1 The email account ... does not exist: Next step: contact the family to check the email address and update in EnrolNow One
5.7.1 Rejected by spam filter: Next step: Please discuss with EnrolNow One whether there are opportunities for improved email integrations that may help mitigate this issue. When underlying issue has been addressed, EnrolNow can request these emails be unblocked by Zoho.
5.4.4 DNS Error... Domain not found: Next step: check the email address, an easy correction may be available
4.2.2 The email account that you tried to reach is over quota: Next step: contact the family to advise their email is showing as full and see if an alternative email account is available.
5.2.2 Mailbox full: Next step: contact the family to advise their email is showing as full and see if an alternative email account is available.