Inbound error codes
Understanding Email Transfer Error Responses
This page lists and tries to explain errors you may have received while attempting to deliver messages to Vade Managed Service. The SMTP response you received contains a unique code starting with OXSUS_. Find the code below to explain the issue you are experiencing and find remediation tips.
_101
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because your email provider is listed on the Vade Threat Network list. If you think this blocking is not justified you can fill out an abuse request
This list contains IP addresses which have been identified as sending spam. We use this list to protect our subscribers from receiving spam.
_102
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because your email provider is listed on the Validity Blocklist. Please go to Validity Unlisting Webpage to get unlisted.
This list contains IP addresses which have been identified as sending spam. We use this list to protect our subscribers from receiving spam.
_103
421 4.2.1 Connection deferred
Vade Managed Service platform protects its users. We could not accept your email at the moment because the server is experiencing issues delivering to backend servers. There are too many messages in queue at the moment. You may retry delivering the message at a later time.
_105
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. The delivery is rejected as there is no reverse dns in place. Sending system's dns should be re-configured and message may be resent.
_106
550 5.7.1 Sender Blocked
Vade Managed Service platform protects its users. We could not accept your email because your email provider is listed on the Abusix Blacklist. Please go to Abusix Look up Webpage to see status.
This list contains IP addresses who are not allowed to send directly to any SMTP server. We use this list to protect our subscribers from receiving spam.
_107
550 5.7.1 Sender Blocked
Vade Managed Service platform protects its users. We could not accept your email because your email provider is listed on the Abusix Blocklist. Please go to Abusix Look up Webpage to see status.
This list contains IP addresses who are not allowed to send directly to any SMTP server. We use this list to protect our subscribers from receiving spam.
_108
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. The delivery is rejected as there is no forward confirmed reverse dns in place. Sending system's dns should be re-configured and message may be resent.
_110
421 4.2.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because the email provider has opened too many connections from a single IP address. The message may be retried using a different SMTP session.
_130
421 4.2.1 Connection refused
Vade Managed Service platform protects its users. We monitor the spam ratio from your mail delivery system over a given time period. This message informs you that your mail delivery system has exceeded the spam ratio over a given period of time, and that the message may be retried at a later time.
_133
421 4.2.1 Connection refused
Vade Managed Service platform protects its users. We monitor the number of invalid recipients over a given time period. This message informs you that your mail delivery system has reached the maximum number of bad recipients over a given period of time, and that the message may be retried at a later time.
_136
421 4.2.1 Connection refused
Vade Managed Service platform protects its users by monitoring and if needed, rate limiting all inbound email traffic. This message informs you that the IP address of the mail delivery system has reached its limit by sending too many messages, and that the message may be retried at a later time.
_139
421 4.2.1 Connection refused
Vade Managed Service platform protects its users by monitoring and if needed rate limiting all inbound email traffic. This message informs you that the IP address of the mail delivery system has reached its limit by opening too many connections, and that the message may be retried at a later time.
_142
421 4.2.1 Connection refused
Vade Managed Service platform protects its users by checking the number of recipients your mail delivery system sent messages to over a given time period. This message informs you that your mail delivery system has reached the maximum number of recipients over a given period of time, and that the message may be retried at a later time.
_201
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because your email provider is listed on the Vade Threat Network list. If you think this blocking is not justified you can fill up a abuse request
This list contains IP addresses which have been identified as sending spam. We use this list to protect our subscribers from receiving spam.
_202
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because your Helo is not resolvable. For more information on troubleshooting this, please refer to rfc5321.
_204
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because your Helo is not resolvable. For more information on troubleshooting this, please refer to rfc5321.
_301
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because the format of the sender address provided as part of the MAIL FROM command is invalid. Double check the sender address and try again later.
_303
421 4.2.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because the sender domain is invalid or could not be verified. In other words we were not able to resolve that domain to an A or MX DNS record. The sender domain dns record needs to be corrected and sending may be retried later.
_305
421 4.2.1 Connection deferred
Vade Managed Service platform protects its users by rate limiting the number of transactions allowed in a single SMTP session. The current limit is set to 50 transactions per session. You may retry to deliver the message by disconnecting and using a new session.
_306
550 5.7.1 Connection refused
Vade Managed Service platform protects its users by using blacklisting based on behaviour. The mail from or mail from domain is blacklisted in the platform. We use this list to protect our subscribers from receiving spam.
_402
550 5.7.1 Recipient rejected
Vade Managed Service platform protects its users. We could not accept your email because the message was sent to a non-existent customer/user. These errors should be treated as an "unsubscribe" by the sender, if a bulk mailer.
_403
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because the message was sent to a non-existent customer/user. These errors should be treated as an "unsubscribe" by the sender, if a bulk mailer.
_404
421 4.2.1 Connection refused
Vade Managed Service platform protects its users by enforcing tresholds on the number of recipients per message allowed in a single SMTP session over a given period of time. You may retry to deliver the message at a later time in a new session.
_405
421 4.2.1 Connection refused
Vade Managed Service platform protects its users by enforcing tresholds on number of recipients allowed for a single message. Your message has exceeded the treshold for number of recipients per message. Reduce number of recipients per message and retry sending later.
_406
550 5.7.1 Connection refused
Vade Managed Service platform protects its users. We could not accept your email because the format of the recipient's address provided as part of an RCPT TO command is invalid. Double check the format of the recipient address and retry sending later.
_407
450 4.2.0 Recipient temporarily unavailable
Vade Managed Service platform protects its users. We could not accept your email because the message was sent to a user that is temporarily unavailable. Try sending again later.
_510
552 5.3.4 Message size limit exceeded
Vade Managed Service platform protects its users. We could not deliver your email because it exceeds the maximum size allowed on our servers, which is currently set to 28MB (29360128 bytes). Reduce message size and try sending again later.
_511
550 5.7.1 Message rejected
Vade Managed Service platform protects its users. We could not resolve your from header address which appears to be empty. Please double check the from address and from domain and try sending again.
_512
550 5.7.1 Message rejected
Vade Managed Service platform protects its users. Your message has been rejected due to from domain not being resolvable.
Double check the from address domain and retry sending later.
_513
550 5.7.1 Message rejected
Vade Managed Service platform protects its users. Your message has been rejected due to a sender blacklist configured by the recipient.
_514
550 5.7.1 Message rejected per sender's policy
Vade Managed Service platform protects its users. Your message did not pass authentication enforced by the sender (SPF, DKIM or DMARC). For more information, please refer to RFC 8616.