I sent numerous test messages and examined the logs and the headers without finding anything. Then I fell back on that old standby and reinstalled Mercury.

It all seems to be working fine now, whatever the problem was.

 Thanks Rolf for your suggestions, at least I understand a bit more about how it is supposed to work now.

I have, for some time, been running Mercury V4.62 on a single machine, using MercuryD to collect mail from 3 POP servers and deliver it to half a dozen mailboxes, without significant problems.

 I have recently added a fourth POP server and the mail from this site is not being delivered correctly. In the setup for MercuryD if I enter a user in the 'Local user' box all mail is correctly delivered to that user. If, however, I leave that blank and enter a user in the 'Default user' box (what I want to do) then all the mail gets delivered there, even when addressed to another valid user. If I leave both boxes empty the mail is deleted, even when addressed to a valid user.

The POP3 Host is the same for all 4 sites and the mailbox definitions are identical (as far as I can see) except of course for the Username and password. The other 3 sites continue to work correctly, It is only the new one that is causing a problem. Everything is on the same machine, the mailboxes are all simple names, 8 characters or less. I am not using Aliases.

Have I missed some obvious setting?

You should start with checking the headers in the received messages to see if there is some other field with recipient information used by this server that might confuse MercuryD. Make sure you see all headers, some are usually hidden by default in the mail client.

/Rolf

[quote user="Rolf Lindby"]

You should start with checking the headers in the received messages to see if there is some other field with recipient information used by this server that might confuse MercuryD. Make sure you see all headers, some are usually hidden by default in the mail client.

[/quote]

 I don't think this can be it. The same test messages sent to the old sites are sorted correctly, when sent to the new site they all go to the Default user. The fact that I get a 'User not found' message when both the Local user and Default user fields are empty suggests that none of the mailboxes are being automatically identified. Except that they are for the other sites!

As I said in the op the POP3 Host is the same for all the sites.

Make sure settings for Optional special header processing are the same as for the other POP3 accounts. If they are you will still need to examine message files headers to see if there is something that can explain it there.

/Rolf