You may run into this error when the mail server fails to process all the recipients specified in the email. For example, most email clients have a maximum number of recipients that a sender can include in the "To", "CC", and "BCC" fields, and when this defined number exceeds, you will encounter this error.
Review your SMTP server's guidelines and provide the supported number of recipients per email. For example, Amazon SES allows you to attach 50 recipients per email. Therefore, use only 50 or less than 50 recipients in your "To", "CC", and "BCC" fields.
If the number of recipients exceeds the allocated quota, split the recipients into several batches and send the email per batch.
View all errors