LTE Module Series
EC2x&EG9x&EM05 SMTP AT Commands Manual
EC2x&EG9x&EM05_SMTP_AT_Commands_Manual 25 / 31
4.3. DNS Parse Fails
When executing AT+QSMTPPUT command, if
“+QSMTPPUT: 653,0” is returned, please check the
following aspects:
1. Make sure the domain name of SMTP server is valid.
2. Query the status of PDP context by AT+QIACT? command to make sure the specified PDP context
has been activated successfully.
4.4. Error Response of AT+QSMTPPUT
“+QSMTPPUT: <err>,<protocol_error>” will be returned after executing AT+QSMTPPUT.
If <err> is not 0, it indicates the sending is failed. Please resend the email. If resending is not successful,
please deactivate the PDP context by AT+QIDEACT and re-activate the PDP context by AT+QIACT to
resolve this issue. If activating the PDP context fails, please refer to
Chapter 4.2
to resolve it.
If the <protocol_error> is not 0, it indicates the error code replied from SMTP server. Customers can
check the issue depending on the protocol error code. For example, if <protocol_error> is 535
(authentication failed), it indicates <username> or <password> may be wrong. If <protocol_error> is 530
(access denied), it means the emails are sent too often, and the SMTP server rejects to post the emails.
For more details, please refer to
RFC2821
(Simple Mail Transfer Protocol).