When reading the postmaster's mailbox and you see as part of the headers/errors at the beginning of message something similar to:

----- Transcript of session follows ----- > > 554 Too many hops 26 (25 max): from via mail.Virginia.EDU, to

You are being told that the mail system sent the message to the first address (in this instance, mst3k@virginia.edu) which sent it to the second address (in this instance, mst3k@m.mail.virginia.edu). The mail system will attempt to deliver such a message 25 times, at which point it will send the message to a postmaster address for processing by a human (that's you!)

To fix the problem:

• Determine the system on which the id is registered - from upostmst, use: ckaddr id
• If you have admin privileges:
  • logon to the system where the person is registered (in this instance, you would logon to config.mail.virginia.edu)
  • become the customer
  • check the forward file: if the forward points to the person's registered address, that is what is causing the loop
  • if needed, reset the forward file to remove the loop
  • exit the
  • person's account
  • send a message to the person from postmaster explaining that the forward on their account to their registered address was causing a mail loop, which meant that messages to them could not be delivered. Tell them that you have removed the forward so that messages could be delivered to them, and that you will redirect to them the message(s) postmaster had received for them.
  • forward the message(s) you have for them to them - it usually useful to use something similar to:

    pick mst3k | mail -f mst3k@virginia.edu

• If you do not have admin privileges:

• send email to unix-backup@virginia.edu (or go and find the unix- backup-du-jour and talk to them)
• explain that postmaster has received messages that indicate a mail loop for a customer and provide the customer's id
• ask them to check the customer's forward file and tell them the system on which the forward file needs to be checked
• ask them to let you know what they find
• when they tell you that the situation appears to be resolved, send a message to the person from postmaster explaining that the forward on their account to their registered address was causing a mail loop, which meant that messages to them could not be delivered. Tell them that you have removed the forward so that messages could be delivered to them, and that you will redirect to them the message(s) postmaster had received for them.
• forward the message(s) you have for them to them - it usually useful to use something similar to:

  pick mst3k | mail -f mst3k@virginia.edu