Solution:

This entry deals with the following errors:

A) Returned mail: User unknown
B) Returned mail: Host unknown
C) 554: service unavailable
D) Message size exceeds fixed maximum messages size

A) Returned mail: User unknown

If you receive a message with the subject:

Returned mail: User unknown

Then the following is a possible list of problems:

1) You typed the email address in incorrectly. Go back and make sure you are typing the correct address.

2) The account has been deleted.

If the account is a Georgia Tech student or staff account (i.e. gt9999x@mail.gatech.edu or first.last.@dept.gatech.edu) then you can log into ACME and type:

lu <account>

If the account shows as INACTIVE, then the account has been removed (either due to termination of employment or the student is no longer registered as a student at Georgia Tech)

If the account is off campus, then you should attempt to contact them and inquire on their account's status (via phone/postal mail). They may have cancelled the account or received a new one.

Another possibility is to e-mail postmaster@email.address.com. For example, if I received returned mail when I sent a message to johndoe@foo.com, then I would send an inquiry to postmaster@foo.com.

OIT has no responsibility for accounts that are not administrated on OIT machines.

This includes many accounts managed by departments, such as user@me.gatech.edu, user@cc.gatech.edu, user@ece.gatech.edu, user@isye.gatech.edu, etc.  If you have a problem with an address that belongs to one of the non-OIT departments on campus, you will have to contact someone in that department (probably the Computer Support Representative) to find a valid email address for the person you want to contact.

B) Returned mail: Host unknown

If you receive a message with the subject:

          Returned mail: Host unknown

Then the following is a possible list of problems:

1) You typed the email address in incorrectly. Go back and make sure you are typing the correct address.

2) The site that hosted the email no longer exists. You will need to contact the person (via phone/postal mail) and inquire as to the account's status.

OIT has no responsibility for accounts that are not administered on OIT machines.

C) 554: service unavailable

If you get the error from an OIT machine "554: service unavailable", then that generally means the user is over his or her disk quota, and will not be allowed to receive email until he or she removes some files.

D) Message size exceeds fixed maximum messages size

If there is a header above the "554: Service unavailable" that says
"552: <address-you-were-mailing-to>... Message size exceeds fixed maximum messages size (2097152)" then that means the message you sent was too large, over two megabytes, and the server you were sending it to will not accept a message that large.  The only thing you can do at that point is reduce the size of the message somehow, perhaps by splitting it into pieces or compressing (zipping) it.

Feel free to submit a request for help for any of the following reasons: