I just got a Windows Phone 8, and it is refusing to connect to my Zimbra server. I'm using the same connection setup as I did in Windows Phone 7, but it just doesn't want to work.

I turned on imap TRACE logging, and here's what I see when I try to sync:

Code:
2012-11-14 21:53:02,351 INFO  [ImapSSLServer-8] [] imap - [10.19.98.1] connected
2012-11-14 21:53:02,351 TRACE [ImapSSLServer-8] [] imap - S: * OK cumorah.puddlestheshark.local Zimbra IMAP4rev1 server ready
2012-11-14 21:53:02,458 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - C: A2 NOOP
2012-11-14 21:53:02,458 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - S: A2 OK NOOP completed
2012-11-14 21:53:02,531 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - C: A3 CAPABILITY
2012-11-14 21:53:02,531 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - S: * CAPABILITY IMAP4rev1 AUTH=PLAIN AUTH=X-ZIMBRA ACL BINARY CATENATE CHILDREN CONDSTORE ENABLE ESEARCH ESORT I18NLEVEL=1 ID IDLE LIST-EXTENDED LIST-STATUS LITERAL+ LOGIN-REFERRALS MULTIAPPEND NAMESPACE QRESYNC QUOTA RIGHTS=ektx SASL-IR SEARCHRES SORT THREAD=ORDEREDSUBJECT UIDPLUS UNSELECT WITHIN XLIST
2012-11-14 21:53:02,532 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - S: A3 OK CAPABILITY completed
2012-11-14 21:53:02,606 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - C: A4 LOGIN ...
2012-11-14 21:53:02,606 INFO  [ImapSSLServer-8] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - user djm@puddlestheshark.com authenticated, mechanism=LOGIN [TLS]
2012-11-14 21:53:02,606 TRACE [ImapSSLServer-8] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - S: A4 OK [CAPABILITY IMAP4rev1 ACL BINARY CATENATE CHILDREN CONDSTORE ENABLE ESEARCH ESORT I18NLEVEL=1 ID IDLE LIST-EXTENDED LIST-STATUS LITERAL+ LOGIN-REFERRALS MULTIAPPEND NAMESPACE QRESYNC QUOTA RIGHTS=ektx SASL-IR SEARCHRES SORT THREAD=ORDEREDSUBJECT UIDPLUS UNSELECT WITHIN XLIST] LOGIN completed
2012-11-14 21:53:02,668 INFO  [ImapSSLServer-8] [] imap - dropping connection for user djm@puddlestheshark.com (server-initiated)
2012-11-14 21:53:02,668 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - S: * BYE cumorah.puddlestheshark.local Zimbra IMAP4rev1 server closing connection
2012-11-14 21:53:02,668 INFO  [ImapSSLServer-8] [] ProtocolHandler - Handler exiting normally
2012-11-14 21:53:02,892 INFO  [ImapSSLServer-8] [] imap - [10.19.98.1] connected
2012-11-14 21:53:02,892 TRACE [ImapSSLServer-8] [] imap - S: * OK cumorah.puddlestheshark.local Zimbra IMAP4rev1 server ready
2012-11-14 21:53:02,917 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - C: A5 NOOP
2012-11-14 21:53:02,918 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - S: A5 OK NOOP completed
2012-11-14 21:53:03,008 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - C: A6 CAPABILITY
2012-11-14 21:53:03,008 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - S: * CAPABILITY IMAP4rev1 AUTH=PLAIN AUTH=X-ZIMBRA ACL BINARY CATENATE CHILDREN CONDSTORE ENABLE ESEARCH ESORT I18NLEVEL=1 ID IDLE LIST-EXTENDED LIST-STATUS LITERAL+ LOGIN-REFERRALS MULTIAPPEND NAMESPACE QRESYNC QUOTA RIGHTS=ektx SASL-IR SEARCHRES SORT THREAD=ORDEREDSUBJECT UIDPLUS UNSELECT WITHIN XLIST
2012-11-14 21:53:03,008 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - S: A6 OK CAPABILITY completed
2012-11-14 21:53:03,087 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - C: A7 LOGIN ...
2012-11-14 21:53:03,087 INFO  [ImapSSLServer-8] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - user djm@puddlestheshark.com authenticated, mechanism=LOGIN [TLS]
2012-11-14 21:53:03,087 TRACE [ImapSSLServer-8] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - S: A7 OK [CAPABILITY IMAP4rev1 ACL BINARY CATENATE CHILDREN CONDSTORE ENABLE ESEARCH ESORT I18NLEVEL=1 ID IDLE LIST-EXTENDED LIST-STATUS LITERAL+ LOGIN-REFERRALS MULTIAPPEND NAMESPACE QRESYNC QUOTA RIGHTS=ektx SASL-IR SEARCHRES SORT THREAD=ORDEREDSUBJECT UIDPLUS UNSELECT WITHIN XLIST] LOGIN completed
2012-11-14 21:53:03,154 INFO  [ImapSSLServer-8] [] imap - dropping connection for user djm@puddlestheshark.com (server-initiated)
2012-11-14 21:53:03,154 TRACE [ImapSSLServer-8] [ip=10.19.98.1;] imap - S: * BYE cumorah.puddlestheshark.local Zimbra IMAP4rev1 server closing connection
2012-11-14 21:53:03,154 INFO  [ImapSSLServer-8] [] ProtocolHandler - Handler exiting normally
The phone just gives an error code "80072F30", which doesn't tell me a thing (Google only reveals a handful of hits, which at best just have a forum post reporting the error (with no resolution), when it is related at all).

Compare this to another client (Windows 8 desktop mail) connecting to the same server/account (I removed a guid and client version number to satisfy my own paranoia):
Code:
2012-11-14 22:01:53,068 INFO  [ImapSSLServer-10] [] imap - [10.19.98.1] connected
2012-11-14 22:01:53,068 TRACE [ImapSSLServer-10] [] imap - S: * OK cumorah.puddlestheshark.local Zimbra IMAP4rev1 server ready
2012-11-14 22:01:53,159 TRACE [ImapSSLServer-10] [ip=10.19.98.1;] imap - C: SF20 CAPABILITY
2012-11-14 22:01:53,159 TRACE [ImapSSLServer-10] [ip=10.19.98.1;] imap - S: * CAPABILITY IMAP4rev1 AUTH=PLAIN AUTH=X-ZIMBRA ACL BINARY CATENATE CHILDREN CONDSTORE ENABLE ESEARCH ESORT I18NLEVEL=1 ID IDLE LIST-EXTENDED LIST-STATUS LITERAL+ LOGIN-REFERRALS MULTIAPPEND NAMESPACE QRESYNC QUOTA RIGHTS=ektx SASL-IR SEARCHRES SORT THREAD=ORDEREDSUBJECT UIDPLUS UNSELECT WITHIN XLIST
2012-11-14 22:01:53,159 TRACE [ImapSSLServer-10] [ip=10.19.98.1;] imap - S: SF20 OK CAPABILITY completed
2012-11-14 22:01:53,273 TRACE [ImapSSLServer-10] [ip=10.19.98.1;] imap - C: PGBB ID ("version" "16.<version number removed>" "os" "WINDOWS" "vendor" "ASUSTeK Computer Inc." "device" "K70AB" "AGUID" "MSFT-<guid removed>")
2012-11-14 22:01:53,273 DEBUG [ImapSSLServer-10] [ip=10.19.98.1;] imap - IMAP client identified as: {AGUID=MSFT-<guid removed>, device=K70AB, os=WINDOWS, vendor=ASUSTeK Computer Inc., version=16.<version number removed>}
2012-11-14 22:01:53,273 TRACE [ImapSSLServer-10] [ip=10.19.98.1;] imap - S: * ID ("NAME" "Zimbra" "VERSION" "7.2.1_GA_2790" "RELEASE" "20120815212042")
2012-11-14 22:01:53,273 TRACE [ImapSSLServer-10] [ip=10.19.98.1;] imap - S: PGBB OK ID completed
2012-11-14 22:01:53,362 TRACE [ImapSSLServer-10] [ip=10.19.98.1;] imap - C: 8I3Z LOGIN ...
2012-11-14 22:01:53,362 INFO  [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - user djm@puddlestheshark.com authenticated, mechanism=LOGIN [TLS]
2012-11-14 22:01:53,363 TRACE [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - S: 8I3Z OK [CAPABILITY IMAP4rev1 ACL BINARY CATENATE CHILDREN CONDSTORE ENABLE ESEARCH ESORT I18NLEVEL=1 ID IDLE LIST-EXTENDED LIST-STATUS LITERAL+ LOGIN-REFERRALS MULTIAPPEND NAMESPACE QRESYNC QUOTA RIGHTS=ektx SASL-IR SEARCHRES SORT THREAD=ORDEREDSUBJECT UIDPLUS UNSELECT WITHIN XLIST] LOGIN completed
2012-11-14 22:01:53,464 TRACE [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - C: 1TQG XLIST "" "*"
2012-11-14 22:01:53,465 TRACE [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - S: * XLIST (\HasChildren \Inbox) "/" "INBOX"
<other folders listed, then...>
2012-11-14 22:01:53,466 TRACE [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - S: 1TQG OK XLIST completed
2012-11-14 22:01:53,951 TRACE [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - C: L6EH SELECT "INBOX"
2012-11-14 22:01:53,952 DEBUG [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - opening folder: INBOX
2012-11-14 22:01:53,953 DEBUG [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap -   ** iterating (collapseExpunged)
2012-11-14 22:01:53,953 DEBUG [ImapSSLServer-10] [name=djm@puddlestheshark.com;ip=10.19.98.1;] imap - copying message data from existing session: INBOX
<and it goes on from there>
No earthly idea what I'm doing wrong. Windows Phone 7 worked fine with the exact same setup.