SMTP error 523 occurs when the email size exceeds the recipient's email server limits. These limits are set by the email server and only allow emails of a specific size to be accepted.
Verifying the email server limits before sending emails is one of the solutions to this error. These limits are available within the email server, and the email recipient or the server administrator may provide this information.
To avoid this error from recurring, ensure that all emails sent to the email server are within the set size limits.
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