Email Non-Delivery Reports
Frequently Asked Questions
May 12, 2005
Q: Why didn't my email get sent? (or Why didn't my email get delivered?)
-or- What does this NDR (Non-Delivery Report) mean?
-or- What does "delivery has been delayed" mean?
Comments:
Generally, it's the last line of the non-delivery report that has the key information, but not always. There is no universal format for NDRs, so you may have to do a bit of investigative work to interpret the results.
Please don't ignore non-delivery reports!
When you attempt to send an email to a "bad" (maybe) address, you will get back a Non-Delivery Report (aka NDR, or "bounce") email. Please take a moment to look at that message because it may tell you a lot about why the mail delivery failed. Some real examples are shown further below, collected from messages that have failed to go out from Perimeter.
Also, please, please, please, if you discover that we have a bad address in Shelby, or in the Global Address List, please don't ignore it! If the bad address is from Shelby, simply send the NDR to the Data Entry email address for the Data Divas to investigate. If the NDR is from something in the Global Address List, then please notify helpdesk. (Of course, in either case, if you know what needs to be corrected, that's very helpful)
General thought: if an email is worth sending, isn’t it worth making sure it gets to the recipient? If you’re not willing to check out addressing problems, then are you sure the email was worth sending?
And, forgive me for highlighting the obvious: If you send an email to a bad address and get back an NDR, and if you then resend to that very same bad address, what do you think is likely to happen that second time? Right -- and we've got hundreds of examples where our very own staff have done that. Please don't be a statistic!
OK, now for those examples.
#1: User Unknown
on 10/3/2002 11:45 AM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;550 ...User unknown>
Tony's simple explanation: This is a bad email address. There's nothing wrong with @mindspring.com, but what's in front of it is not a valid account. [and if you choose to re-send this message, it will fail again]
#2: You don’t have permission
EVT - Events on 10/3/2002 11:37 AM
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<gabriel.perimeter.org #5.7.1>
Tony's simple explanation: We don't let people mail to each other's departments. It's a fact, and no matter how many times you try, it will still fail. There may be other reasons for this message, but it usually means an intentional blocking at the source, not at the recipient.
#3: Invalid Recipient
on 10/3/2002 9:25 AM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;550 Invalid recipient: <>
Tony's simple explanation: Same as for #1, just a different message. Graybrd isn't a valid email name at attbi.com.
#4: exceeded storage allocation
on 10/3/2002 8:31 AM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;552 Requested action not taken: exceeded storage allocation>
Tony's simple explanation: This is a common problem with hotmail. Because of the size restrictions on a hotmail account, plus the typically massive volume of spam hotmail accounts receive, mailboxes get full very easily. If the user doesn't check often, this is the result. This is not necessarily a bad address! This is simply a case of a hotmail user not having checked his or her email recently enough (or not deleting enough). Re-sending "now" will likely fail again. Re-sending later might work.
#5: not a valid mailbox
on 10/2/2002 9:36 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;550 <> is not a valid mailbox>
Tony's simple explanation: Same as for #1, just a different error message. Mchaelp isn't a valid email name at aaahawk.com. [Editorial: I bet adding an 'i' between the m and the c would fix this one!]
#6: Could not deliver in the time limit specified
on 10/2/2002 8:20 PM
Could not deliver the message in the time limit specified. Please retry or contact your administrator.
<gabriel.perimeter.org #4.4.7>
Tony's simple explanation: This one is harder to explain. For reasons that aren't clear, we weren't able to get a message from Perimeter to @home.net. It doesn't necessarily mean this is a bad address, but it's quite possible. It could just be a case of home.net being down for maintenance, or temporarily off-line, but it strongly implies that it's been unreachable for several days.
#7: e-mail account does not exist
/o=PERIMETER/ou=SITE1/cn=Recipients/cn=RayE on 10/2/2002 5:33 PM
The e-mail account does not exist at the organization this message was sent to. Check the e-mail address, or contact the recipient directly to find out the correct address.
<gabriel.perimeter.org #5.1.1>
Tony's simple explanation: This is most likely a contact record that's out of date. The most common cause of this is duplicating something we have in the GAL into your own personal contacts -- a generally bad idea for just this reason! Recognizing problems at our end vs. at the recipient end may not be obvious, but in either case, the indicator is of a specific email account, not the domain.
#8: no such address at this site
on 10/2/2002 5:26 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;501 Invalid recipient address (no such address at this site)>
Tony's simple explanation: Another variation of #1. beth.grabenkort is not a valid email address at furman.edu.
#9: User unknown
on 10/2/2002 5:15 PM
The e-mail account does not exist at the organization this message was sent to. Check the e-mail address, or contact the recipient directly to find out the correct address.
<gabriel.perimeter.org #5.1.1 smtp;550 5.1.1 <>... User unknown>
Tony's simple explanation: Same thing again, just a different variation of the message.
#10: Mail quota exceeded
on 10/2/2002 5:15 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;554 Mail quota exceeded>
Tony's simple explanation: Similar to the hotmail problem, but a different message from juno. The address is probably fine, but until the mailbox is cleaned out, you can't get another message there.
#11: destination server…could not be found
on 10/2/2002 5:15 PM
The destination server for this recipient could not be found in Domain Name Service (DNS). Please verify the email address and retry. If that fails, contact your administrator.
<gabriel.perimeter.org #5.4.0>
Tony's simple explanation: The problem here is on the right side of the "@." panther.gsu is not a valid email system address. Roughly the same as a US Post Office return of "no such street." [Editorial. Adding a .edu on the end might help a lot]
#12: multiple rejects together
on 10/2/2002 5:14 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;552 Requested action not taken: exceeded storage allocation>
on 10/2/2002 5:14 PM
The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator.
<gabriel.perimeter.org #2.0.0 smtp;250 >
on 10/2/2002 5:14 PM
The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator.
<gabriel.perimeter.org #2.0.0 smtp;250 >
Tony's simple explanation: These 3 errors were all in the same NDR message. The first one is clear (another full mailbox). But the second two don't really tell us anything. Usually this is a case of Hotmail rejecting all the messages that were sent together because of the failure of the first one. A re-send to these later addresses is likely to be successful. Unfortunately, we don't have control over the way hotmail chooses to mass-reject a batch of mail.
#13: Quota violation
on 10/2/2002 5:14 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;554 Quota violation for >
Tony's simple explanation: Another way of saying "mailbox" full. Or, perhaps just a single message that is larger than what the receiving system allows. We allow messages as large as 1.5MB to go out. Some receiving systems limit incoming mail to a much smaller size. (Mindspring is typically about 3MB/message limit, so this points back to a full mailbox as the most likely problem)
#14: Hitting spamtrap
Jill Scoggins on 10/2/2002 4:34 PM
The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator.
<gabriel.perimeter.org #5.0.0 smtp;550 5.0.0 <>... Administrative Prohibition - < - Hitting spamtraps>
Tony's simple explanation: The receiving mail system blocked a spam! (Good for them)
#15: bad format, and then some
// on 10/2/2002 2:06 PM
The format of the e-mail address is incorrect. Check the address, look up the recipient in the Address Book, or contact the recipient directly to find out the correct address.
<gabriel.perimeter.org #5.1.3>
Tony's simple explanation: Wow -- there are all kinds of issues here, but the bottom line is this is nowhere near a good email address. [modern] Email addresses will NEVER contain slashes. Very few email addresses will have www at the start, either.
#16: Account Inactive
on 10/2/2002 1:49 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;550 Account Inactive>
Tony's simple explanation: This is Juno's kind way of saying this used to be a good address, but nobody uses it any more.
#17: Could not deliver message in the time specified
on 10/2/2002 1:30 PM
Could not deliver the message in the time limit specified. Please retry or contact your administrator.
<gabriel.perimeter.org #4.4.7>
Tony's simple explanation: This is another hard one. It implies gateway.net isn't responding and hasn't been for a while. Most likely this is a formerly good domain that is no longer in use. Or it could be down for service, or there could be network connectivity issues.
#18: No such address
on 10/2/2002 1:05 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;550 No such address>
Tony's simple explanation: *best guess* This may be a couple of problems. At first glance, it looks like jlr isn't valid at Bellsouth.com, but then you have to wonder about that 'snt' in front of bellsouth. There's probably a typo here, but it's not extremely obvious what it is.
#19: User unknown
Stoudenmire, Marybeth on 10/3/2002 2:51 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<gabriel.perimeter.org #5.5.0 smtp;550 <>: User unknown>
Tony's simple explanation: This is a goodie and a common one. Although mediaone.net is technically still a valid name, when AT&T took over, they renamed everything to attbi.com. The user name may or may not be valid, but you can safely assume that anything ending with @mediaone.net is going to bounce. Since Comcast took over, attbi.net has become Comcast.net, so this gets even more fun!
#20: Mailbox Unavailable (hotmail)
Somewhat like #16. This is an address that has seemingly been abandoned, but could theoretically still be retrieved by the recipient. But, if they haven’t checked their mail in 30 days, does it matter?
#21: Unable to relay
on 5/11/2005 7:33 AM
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<Joseph.perimeter.org #5.7.1 smtp;550 5.7.1 Unable to relay for >
This is one of the most challenging and it could mean a number of things. It almost always represents a problem at the receiving end, but it might be influenced by things at our end. More often than not, this will require coordinated efforts of both the sending and receiving postmasters to resolve. It’s one of the few cases where sending to “postmaster” at the other domain makes sense.
Delivery Delayed notifications
Q:What is a Delivery Status Notification (Delay)?
What does "Delivery to the following recipient has been delayed" mean?
A:Short answer: your mail has not YET been delivered, but the system is still trying.
First, a restatement of the obvious. Note the different items contained in the notification:
- "This is an automatically generated Delivery Status Notification" Means what it says. Tony Dye did not personally send you this message -- the system created it automatically. It only has Tony's name on it because he's the email System Administrator.
- "YOU DO NOT NEED TO RESEND YOUR MESSAGE." Also means exactly what it says. Your email has NOT failed (at least not yet); you don't need to do anything else. However, it might be a good time to start thinking ahead and look closely at the address your email was sent to -- maybe there is a real problem and maybe you can do something about it.
- "Delivery to the following recipients has been delayed." Again, just what it says. The recipient hasn't yet received the email
The underlying story here is that you've sent a message to what appears to be a valid address. Our mail server looked up the information on the mail server you tried to contact and it seems to be valid, but for whatever reason, the two mail servers haven't been able to connect for the actual delivery. This is roughly the same as looking up a phone number in a phone book, calling it, but receiving a "this line is temporarily out of service" type of message. The expectation is that the service will be restored within a few hours or days.
There are plenty reasons why a mail server may be temporarily unreachable. A server could be down for maintenance, an Internet link may be temporarily out, an address change could be taking place, or any of a wide variety of other technical glitches.
There's also the very real possibility that you've chosen a truly wrong address that appears to be valid. There are some unscrupulous folks out there who will register domain names that are almost the same as real domains, perhaps playing up the most common typos.
When you receive this message, it might be a good time to review the email address to see if it's remotely possible that you are the problem, rather than the Internet, or mail servers, or whatever else technical in the world could be wrong.
NICFA 2006Handout 18