YourServing.com - Top Rated Web Hosting
Back to main site

The top portion covers bounce back messages.
  • The x.x.x Codes
  • The xxx Codes
  • Examples of real Error messages with an explaination.
    (the email client errors coming in the future) The 2nd half covers email connection failure messages when using an email client.

    Many people get a failed email message and just know that the mail didn't go through.
    This message is called a bounceback
    What does that message really mean?
    The failed email notice tells you what is wrong and why the email failed
    This way you can determine if it is your email or the one you are sending to.

    Email Error Codes have 3 Digits


    If the 1st digit is a...
    (The 1st digit indicates if the response was good, bad, or incomplete)
    1The Command was accepted, but the action is pending confirmation of a reply
    2The action was completed successfully
    3The command was accepted, but the action is pending receipt of further information.
    4The command was not accepted and the requested action did not occur. These are usually because of a temporary error or condition and one should try resending the request again.
    5The command was not accepted and the requested action did not occur. This is a permanent failure message. Something needs to be fixed before the action will work.

    If the 2nd digit is a....
    0SyntaxUsually refers to a syntax error occurring.
    1InformationReply to a request for information
    2ConnectionsRefers to the channel transmitting
    3 and 4These are undefined still
    5Indicate the status of the receiver's mail system
    There are 2 sets of codes xxx and x.x.x
    x.1.x Codes
    X.1.0Other address statusX.1.1Bad destination mailbox address
    X.1.2Bad destination system addressX.1.3Bad destination mailbox address syntax
    X.1.4Destination mailbox address ambiguousX.1.5Destination mailbox address valid
    X.1.6Mailbox has movedX.1.7Bad sender's mailbox address syntax
    X.1.8Bad sender's system address

    x.2.x Codes
    X.2.0Other or undefined mailbox statusX.2.1Mailbox disabled, not accepting messages
    X.2.2Mailbox fullX.2.3Message length exceeds administrative limit
    X.2.4Mailing list expansion issue

    x.3.x Codes
    X.3.0Other or undefined mail system statusX.3.1Mail system full
    X.3.2System not accepting network messagesX.3.3System not capable of selected features
    X.3.4Message too big for systemX.3.5System incorrectly configured

    x.4.x Codes
    X.4.0Other or undefined network or routing statusX.4.1No answer from host
    X.4.2Bad connectionX.4.3Routing server failure
    X.4.4Unable to routeX.4.5Network congestion
    X.4.6Routing loop detectedX.4.7Delivery time expired

    x.5.x Codes
    X.5.0Other or undefined protocol statusX.5.1Invalid command
    X.5.2Syntax errorX.5.3Too many recipients
    X.5.4Invalid command argumentsX.5.5Wrong protocol version

    x.6.x Codes
    X.6.0Other or undefined media errorX.6.1Media not supported
    X.6.2Conversion required and prohibitedX.6.3Conversion required but not supported
    X.6.4Conversion with loss performedX.6.5Conversion failed

    x.7.x Codes
    X.7.0Other or undefined security statusX.7.1Delivery not authorized, message refused
    X.7.2Mailing list expansion prohibitedX.7.3Security conversion required but not possible
    X.7.4Security features not supportedX.7.5Cryptographic failure
    X.7.6Cryptographic algorithm not supportedX.7.7Message integrity failure

    200 Codes
    211System status / system help reply214Help message
    220Domain service ready221Service closing transmission channel
    250Requested mail action okay and completed251will forward to forwardpath
    252Pending messages for node started. Cannot Verify user, will take message for this user and attempt delivery253pending messages for node started

    300 Codes
    354Start mail input; end with . server is ready to accept the message355Octet-offset is the transaction offset

    400 Codes
    421Domain service not available, closing transmission channel432Domain service not available, closing transmission channel
    450Requested mail action not taken: mailbox unavailable. request refused451Requested action aborted: local error in processing
    Request is unable to be processed, try again
    452Requested action not taken: insufficient system storage453No mail
    454TLS not available due to temporary reason. Encryption required for requested authentication mechanism.458Unable to queue messages for node
    459node not allowed: reason

    500 Codes
    500 server could not recognize the command due to a syntax error501Syntax error, no parameters allowed
    502Command not implemented503Bad sequence of commands
    504Command parameter not implemented510Check the recipient address
    512Host unknown. Domain can not be found.515Destination mailbox address invalid
    517Problem with senders mail attribute, check properties521Machine does not accept mail
    522Recipient has exceeded mailbox limit523Server or connector limit exceeded. Message too large
    530Must issue a STARTTLS command first. Encryption required for requested authentication mechanism531Mail system Full
    533Remote server has insufficient disk space to hold email534Authentication mechanism is too weak. Message too big
    535Multiple servers using same IP538Encryption required for requested authentication mechanism.
    540 No DNS Server for email address541 No answer from host
    542Bad Connection543Routing server failure. No available route
    546Email looping547Delivery time-out.
    550Requested action not taken: mailbox unavailable.551User not local; please try forwardpath
    552Requested mail action aborted: exceeded storage allocation553Requested action not taken: mailbox name not allowed
    554Transaction failed

    (The following are very general error message explainations)
    A message that you sent could not be delivered to one or more of its
    recipients. This is a permanent error. The following address(es) failed:

    The email address is either misspelled, or does not exist.
    help@howtointernet.net
    mailbox is full: retry timeout exceeded
    This is fairly simple and straight forward.
    The email you are sending to can not accept any more data.
    <help@howtointernet.net>:
    Sorry. Although I'm listed as a best-preference MX or A for that host,
    it isn't in my control/locals file, so I don't treat it as local. (#5.4.6)
    There may be an issue with either the DNS setup
    or the port for the mail on that server is not working.
    help@howtointernet.net
    Technical details of permanent failure:
    PERM_FAILURE: DNS Error: Domain name not found
    This message is saying that the domain name "howtointernet.net"
    does not exist. Make sure it is not misspelled.
    help@howtointernet.net
    Technical details of permanent failure:
    PERM_FAILURE: SMTP Error (state 13): 553 sorry, mailbox unavailable (#4.7.1)
    This mailbox may not exist- double check spelling
    This mailbox may exist and the pathway on the server needs to be re-established
    This mailbox may exist, but the DNS is not set up properly.
    <help@howtointernet.net>:
    Connected to 168.144.68.96 but sender was rejected.
    Remote host said: 553 sorry, your mailserver [131.103.218.112] is
    rejected by See http://spamcop.net/
    Your email is being rejected because it is being seen as spam.
    This message specifically shows spamcop is the spam company that blocked the IP address
    The IP address could be the one provided to you by either the company that hosts the email
    Or your internet service provider providing the line you used to send the mail
    You can tell who is being blocked by copying the IP address
    In this example it is: 131.103.218.112 and doing an IP whois lookup
    Check SPAMcop's system here Check another black list systems
    <help@howtointernet.net>:
    209.18.68.11 does not like recipient.
    Remote host said: 550-Rejected message because 131.103.218.80 is in a
    black list at 550 bl.spamcop.net Giving up on 209.18.68.11.
    Your email is being rejected because it is being seen as spam.
    This message specifically shows spamcop is the spam company that blocked the IP address
    The IP address could be the one provided to you by either the company that hosts the email
    Or your internet service provider providing the line you used to send the mail
    You can tell who is being blocked by copying the IP address
    In this example it is: 131.103.218.112 and doing an IP whois lookup
    The IP address 209.18.68.11 is the IP for the person you are trying to send to
    Check SPAMcop's system here Check another black list systems
    help@howtointernet.net
    SMTP error from remote mail server after RCPT TO::
    host 72.22.71.86 [72.22.71.86]: 553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)
    There could be 2 reasons for this.
    1- The sender is not allowed to email this account. (spam filters, blacklisted IP address, recipient has wrong permissions for email files)
    2- The command was aborted because the email address is invalid.
    :
    The e-mail address could not be found. Perhaps the recipient moved to a
    different e-mail organization, or there was a mistake in the address. Check the
    address and try again.
    <"host451"."howtointernet.net" #5.1.0>
    help@howtointernet.net
    Technical details of permanent failure:
    PERM_FAILURE: SMTP Error (state 13): 553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)
    The sender is not allowed to email this account. (recipient has wrong permissions for email files, or sender is being blocked by a spam filter)
    help@howtointernet.net
    SMTP error from remote mail server after RCPT TO::
    host 74.220.202.27 [74.220.202.27]: 550-4.184.96.66.static.eigbox.net
    (bosmailout04.yourhostingaccount.com)
    550-[66.96.184.4] is currently not permitted to relay through this server.
    550-Perhaps you have not logged into the pop/imap server in the last 30 minutes
    550 or do not have SMTP Authentication turned on in your email client.
    Relay not permitted through this server means that either SMTP relay has been disabled or requires authentication such as a password
    Email may be suspended or permissions are set incorrectly. The sender's system may have a blocked port.
    help@howtointernet.net
    Technical details of permanent failure:
    PERM_FAILURE: SMTP Error (state 12): 550 bosauthsmtp11: Host
    209.85.146.182: No unauthenticated relaying permitted
    Relay not permitted through this server means that either SMTP relay has been disabled or requires authentication such as a password
    The password is not authenticating or being recognized. The sender's system may have a blocked port.
    help@howtointernet.net
    SMTP error from remote mail server after initial connection:
    host gateway-f2.isp.att.net [207.115.11.16]: 550-66.96.185.8 blocked by
    ldap:ou=rblmx,dc=bellsouth,dc=net
    550 Blocked for abuse. See http://www.att.net/bls_rbl/ for information.
    The sender's IP address has been blocked for sending SPAM.
    :
    Sorry, I wasn't able to establish an SMTP connection. (#4.4.1)
    I'm not going to try again; this message has been in the queue too long.
    This usually means there is some delay on the server
    It could be the sender's server has a backed up mail system
    Or the receiver's server is taking too long to respond
    :
    See /home/howtointernet/.maildata/users/help/TMDA_DELIVERY_FAILURE for traceback
    I'm not going to try again; this message has been in the queue too long.
    The message was waiting too long because of a delay on the server
    The path shows that there is a log kept of failed messages and it shows the route it went through
    help@howtointernet.net
    Technical details of permanent failure:
    PERM_FAILURE: SMTP Error (state 13): 550 5.1.1 recipient rejected
    The email was rejected by the recieving email system. Usually indicates a problem with the recipent's email address
    help@howtointernet.net
    SMTP error from remote mail server after end of data:
    host mx.tnbnazarene.org [66.96.140.51]: 552 5.7.0 Number of 'Received:' DATA
    headers exceeds maximum permitted
    The email went through too many different channels and is being rejected by the
    server it is being sent to. Too many headers could indicate a spammer or an email
    spoofer trying to route through someone else's mail system.
    this page is still under construction