5.0.0 Address does not exist

Email id invalid or does not exists

5.1.0 Other address status

A problem occurred during the delivery of this message to this email address.

5.1.1 Bad destination mailbox address

Specified from address or domain mailbox does not exists (anything after ‘@’).

5.1.2 Bad destination system address

Address does not exists or not able to accept mails

5.1.3 Bad destination mailbox address syntax

Invalid or corrupted character in email address

5.1.4 Destination mailbox address ambiguous

Check your spelling of email address and resend

5.1.5 Destination mailbox address invalid

Mail address may be invailid or may have spelling mistakes.

5.1.6 Mailbox has moved

Mailbox may be moved to new location

5.1.7 Bad sender’s mailbox address syntax

Sender’s address is invalid syntactically

5.1.8 Bad sender’s system address

Sender’s system in the address does not exist or is incapable of accepting.

5.2.0 Other or undefined mailbox status

This error is usually return for which it has class (ie. 1xx,2xx,3xx,4xx,5xx).

5.2.1 Mailbox disabled, not accepting messages

Some changes need to made mandatory for resending mail

5.2.2 Mailbox full

Try increasing your emailbox space capacity

5.2.3 Message length exceeds administrative limit.

The Size of your email has exceeded its limit try removing unwanted text.

5.2.4 Mailing list expansion problem

mailbox saves your email address to whom you are sending or receiving emails, there is problem saving that email addresses.

5.3.0 Other or undefined mail system status

Mail has been accepted normally

5.3.1 Mail system full

mail system at client’s is not able accept emails

5.3.2 System not accepting network messages

you need to whitelist the email address through your administrator it has been blocked.

5.3.3 System not capable of selected features

5.3.4 Message too big for system

Message character limit has exceeded

5.4.0 Other or undefined network or routing status

Mail accepted routing status is not available

5.4.1 No answer from host

Configuration issue at recipient’s server. you can send again once the issue is resolved at recipient’s end

5.4.2 Bad connection

unable to connected or delay in connection

5.4.3 Routing server failure

Error is generated by the sender’s server, you need to contact your ISP/ESP.

5.4.4 Unable to route

When emailid or hosts provided is invalid.

5.4.5 Network congestion

Multiple connection on single channel.

5.4.6 Routing loop detected

Sending message to same PMTA from you have sent.

5.4.7 Delivery time expired

Mail is queued for 2-3 days after that it is removed by returning above messagae

5.5.0 Other or undefined protocol status

Something went wrong with protocol while delivering mail which can be well expressed with other status code.

5.5.1 Invalid command

out of sequence or unsupported command used while sending mail

5.5.2 Syntax error

unable to interprete the command due wrong syntax or it is unrecognized.

5.5.3 Too many recipients

Number of recipient is greater than the amount of recipient deliver by protocol

5.5.4 Invalid command arguments

the arguments were out of range or represented unrecognized features

5.5.5 Wrong protocol version

protocol version is mis-match which can’t be solved at one go.

5.6.0 Other or undefined media error

Issue with content of the message which cannot be delivered.

5.6.1 Media not supported

Media is not supported by protocol or the system who is going to formard the mail.

5.6.2 Conversion required and prohibited

Message should be converted before it is send/delivery else it will be not delivered.

5.6.3 Conversion required but not supported

Message must be converted in order to be forwared but partically it is not possible.

5.6.4 Conversion with loss performed

This is Warning to the sender that While conversion data may be lost.

5.6.5 Conversion failed

Message conversion was unsuccessful

5.7.0 Other or undefined security status

Something went wrong while validating authentication which can be expressed with other status code.

5.7.1 Delivery not authorized, message refused

Authentication was not successful due to which email was not sent.

5.7.2 Mailing list expansion prohibited

Sending mail is not allowed to particular recipient.

5.7.3 Security conversion required but not possible

Conversion was required to send mail securely which is not possible.

5.7.4 Security features not supported

Authentication not supported at delivery end.

5.7.5 Cryptographic failure

Unable to decrypt the message because the key was wrong or invalid.

5.7.6 Cryptographic algorithm not supported

Unable to decrypt the message because alogrithm was not supported.

5.7.7 Message integrity failure

The message is corrupted or altered