[I didn't see a response to this on-list. Sorry if I'm repeating someone.]
On Mon, 1 Oct 2007, Kenneth Porter wrote:
[...] I forgot to change the pop3_uidl_format setting [...] So he was seeing repeated downloads of all his mail (about 300 MBytes) every time he connected. [...]
Does this setting in fact get used by IMAP? It's in the POP3 section, so I'm wondering if it takes effect when one is using IMAP from the client.
No, it doesn't. IMAP unique identifiers are always 32-bit (unsigned) integers, expressed in base 10. (64 bits when combined with the 32-bit UIDVALIDITY)
cf. RFC 3501 - IMAP 4rev1 discussion: http://tools.ietf.org/html/rfc3501#section-2.3.1.1 syntax: uniqueid - http://tools.ietf.org/html/rfc3501#page-91
POP3 UID's have significantly more variation (hence the dovecot setting):
[ from RFC 1937 - POP 3 - http://tools.ietf.org/html/rfc1939#page-12 ] “The unique-id of a message is an arbitrary server-determined string, consisting of one to 70 characters in the range 0x21 to 0x7E, which uniquely identifies a message within a maildrop and which persists across sessions.”
Best, Ben