[Oberon] Re. UIDL in POP3

[Chris Glur]

peasthope wrote:
> Q.: Why does the Oberon MUA issue the UIDL
> when messages are to be deleted from the server=3F  
> Why not just collect all the messages, delete=20
> all from the server and ignore UID=3F

Mail.Mod [also] uses UIDL in PROC Synchronize, and I also want to 
know the detailed reasons, so I'm posting:

Newsgroups: comp.os.linux.networking,comp.mail.misc
Subject: POP use of UIDL command ?

It's not clear to me from my RFCs: 1939, 1725, 2449 how the 
[list unique IDs of mails still on the server] UIDL is used.

I'm speculating that when a list of mails is left on the server and the
client, then the ability to check/synchronize the 2 lists-of-mails is
needed.  Provision must be made for the possibility of mail[s] being
deleted from either the server or client, without the corresponding
client or server deletion; which would cause a loss of synchronism.

Q - what would the alrogithm be for using such UIDL facility ?

Perhaps:
  ForEach ServerMail: Get the unique-ID;
  Compare with the Client's listing & provide info. re. any miss-match.

Perhaps any mails which are on one only of the server and client,
would be marked as such ?

Forcing  a synchronisation would need deleting the unmatched
mails ?

Thanks for any info.

== Chris Glur.