[Dovecot] POP3 flag updates

[pod]

Timo Sirainen <tss at iki.fi> writes:

> Why does Dovecot add \Seen flag for mails that have been RETRed? Does
> anyone really want to use this feature? I can't remember why I
> implemented it originally, perhaps it was just "because other servers  do
> that too". I'm thinking about at least changing  pop3_no_flag_updates=yes
> to be default.

Doesn't it just keep things looking consistent for a user if they happen
to be using both a POP3 client and an IMAP client?

Sound implausible?  Say for normal use they have a desktop configured that
does POP3 (but doesn't DELE after RETR, obviously) but they are away from
the desk and use a Web to Mail gateway which happens to be an IMAP client.
It is presumably considered a nice feature that messages they last POPped
show up as \Seen in the web interface and consequently stuff that has
arrived since shows up as not \Seen.  Maybe.