Mail Errors
Diagnosing Bounced E-Mails
Non-fatal warnings :
When there is a technical problem with the server at the receiving end, there will be an initial WARNING bounce -- usually within two or four hours -- announcing the delay and stating that continuing attempts at delivery will be made for four or five days:
Fatal immediate rejections :
When the mail is rejected, a bounce will come back quickly, often within seconds -- unless the recipient is on some internal mail system without a direct connection to the Internet. It will look something like this:
User Unknown
----- The following addresses had permanent fatal errors -----<JDOE@HOME.COM>
(reason: 550 5.1.1 <HERE@HOME.COM>... User unknown)
----- Transcript of session follows -----
... while talking to mx-rr.home.com.:
>>> RCPT To:<JDOE@HOME.COM>
<<< 550 5.1.1 <JDOE@HOME.COM>... User unknown
550 5.1.1 <JDOE@HOME.COM>... User unknown
In this example our mail server tried to deliver the message to the mail server at home.com, but the home.com mail server refused to accept it because they have no user known as "jdoe". This could be because the username part of the address (jdoe) was typed incorrectly, or because the "jdoe" account at home.com expired or was cancelled, or because you were trying to reply to a message sent out under a falsified address. In rare cases it can indicate a mail system failure at the remote site.
Host Unknown
----- The following addresses had permanent fatal errors -----<JDOE@HOME.COM>
----- Transcript of session follows -----
550 5.1.2 <JDOE@HOME.COM>... Host unknown (Name server:
mail.MAILSERVER.com: host not found)
This means that our mail server was not able to locate the mail server for mail.MAILSERVER.com (mail.MAILSERVER.com) in the Internet's domain name service (DNS). If the target system can't be found in the DNS, then our mail server can't connect to the remote mail server to deliver your message. Where the address is typed correctly and is a real one, the problem is usually a temporary failure in DNS.
Mail Quota Exceeded
----- The following addresses had permanent fatal errors -----<JDOE@JUNO.COM>
----- Transcript of session follows -----
... while talking to c.mx.juno.com.:
>>> RCPT To:<JDOE@JUNO.COM>
<<< 552 <JDOE@JUNO.COM>... Mail quota exceeded
554 <JDOE@JUNO.COM>... Service unavailable
Many systems impose a quota on the amount of disk space each user's mail box
may use. If a user on such a system exceeds his quota the mail system
refuses to accept any more mail for him and thus rejects the mail.
Message Exceeds Maximum Size
----- The following addresses had permanent fatal errors -----
<JDOE@HOME.COM>
(reason: 552 5.2.3 <JDOE@YOU.com>... Message size exceeds fixed
maximum message size
----- Transcript of session follows -----
... while talking to home.com.:
>>> MAIL From:<JDOE@YOU.com> SIZE=222751
<<< 552 5.2.3 <JDOE@YOU.com>... Message size exceeds fixed maximum message size
554 5.0.0 <JDOE@home.com>... Service unavailable
The only solution is to shorten the message and try again.
Delivery Deferred, Will Keep Trying
************************************************ THIS IS A WARNING MESSAGE ONLY **
** YOU DO NOT NEED TO RESEND YOUR MESSAGE **
**********************************************
----- The following addresses had transient non-fatal errors -----
<JDOE@HOME.COM>
----- Transcript of session follows -----
<JDOE@HOME.COM>... Deferred: Connection refused by home.com.
Warning: message still undelivered after 4 hours
Will keep trying until message is 5 days old
Do nothing! The banner means EXACTLY what it says: you DO NOT need to resend your message. Our mail system will keep trying once per hour until delivery succeeds or until five days elapse, which ever happens first.
Message Could Not Be Delivered For Five Days
----- The following addresses had permanent fatal errors -----<JDOE@HOME.COM>
----- Transcript of session follows -----
<JDOE@HOME.COM>... Deferred: Connection refused by HOME.com.
Message could not be delivered for 5 days
Message will be deleted from queue
Our mail server kept trying once an hour for five days but was still unable to deliver the message, so it gave up trying.
Write a letter, make a phone call, send a FAX. You can resend your e-mai if you want to, but if the intended recipient's mail server couldn't be reached for five days on the first attempt, it probably won't be reachable on the second attempt.
Sender Domain Not Found
----- The following addresses had permanent fatal errors -----<JDOE@HOME.COM>
----- Transcript of session follows -----
... while talking to b.mx.HOME.com.:
>>> MAIL From:<JDOE@BCLP.NET>
<<< 550 <JDOE@YOURDOMAIN.COM>... Sender domain not found in DNS
550 <JDOE@HOME.COM>... Service unavailable
In an attempt to stem the flow of spam e-mail into their systems, many mail systems reject messages where the domain name part of the sender's address (the part after the "@") cannot be found in the DNS. This is effective against some spam because spammers often send out their mass mailings under phony addresses.
Go into your mail program's setup and make sure your e-mail address is entered correctly, then resend your message.
Possible Virus
----- The following addresses had permanent fatal errors -----<JDOE@MEDIAONE.NET>
(reason: 553 5.0.0 Possible virus, see
http://www.symantec.com/avcenter/venc/data/w32.sircam.worm@mm.html)
----- Transcript of session follows -----
... while talking to ndmls01.mediaone.net.:
>>> DATA
<<< 553 5.0.0 Possible virus, see
http://www.symantec.com/avcenter/venc/data/w32.sircam.worm@mm.html
554 5.0.0 <JDOE@MEDIAONE.NET>... Service unavailable
Delivery Errors For E-Mail You Did Not Send :
When a spammer's mass mail software sends out thousands of junk e-mail messages, the address shown on the "From:" line is almost never the spammer's real address. Sometimes it is a completely phony address, but often it is a real address chosen at random from the list of addresses to which the spam is being sent. So when the mail is rejected, it will bounce back to your account. This is often caused by badly set mail server filtering that rejects mail based on email address as apposed to verification based on sender IP, ie Reverse DNS.