What do the numerical email error codes mean? Given below are the explanations for the numerical email error codes:
-1 : Missing Email Address: The destination address field is empty.

-4 : No Server. The SMTP Server is unavailable.Try using the IP Devices feature in the web interface to ping the SMTP server.

Reasons for this error include:
Spelling errors in the server name or IP.
Server name is not resolved by DNS server because DNS server is off or not reachable.
Incorrect configuration of Gateway.
Connection blocked by firewall.

-5 : No mailbox: The destination address is not recognized by the SMTP server. Not a valid email address.

-6 : TCP error: This usually comes in conjunction with error -4 and has the same causes.

-8 : Syntax error.

-13 : General error: This usually is an incorrect sender email address on the Enterprise settings page in the web interface. Also can be caused by account restrictions in the mail server.

-89 : SMTP_SSL_BAD_DATA_ERR

-90 : SMTP_SSL_DATA_ERR

-91 : SMTP_SSL_BAD_FROM_ERR

-92 : SMTP_SSL_BAD_TO_ERR

-93 : SMTP_SSL_BAD_FROM_ERR

-94 : SMTP_SSL_AUTH_FAILURE_ERR

-95 : SMTP_SSL_AUTH_NO_SUPPORT_ERR

-96 : SMTP_SSL_EHLO_ERR

-97 : SMTP_SSL_SERVER_NOT_READY_ERR

-98 : SMTP_SSL_CONN_SEND_ERR

-99 : SMTP_SSL_PROTOCOL_ERR

-100 : SMTP_SSL_CONN_ERR=-100

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