Recipient did not receive email
Email messages are not delivered to the intended recipients.
Receiving email issues might be caused by connection problems, throttling, incorrect email recipient spelling, and email size and attachment limitations.
If you are experiencing connection issues, contact your system or network administrator to troubleshoot and correct the problem.
If throttling is causing delivery issues, you can try the following:
Schedule your emails to deploy over an extended period.
Segment your emails by domain or divide your lists into multiple parts.
Send your emails at earlier times, so that all emails can be sent by their required delivery dates.
Limit the size of individual emails to equal or less than 100 KB to prevent spam filters from sending your emails to the spam folder.
Avoid sending zipped files and use secure file transfer application when sending large attachments, to prevent your emails from being blocked. Additionally, avoid sending attachments that contain macros, as they might be blocked to prevent potential malware from being smuggled.