Walkthrough: https://www.petenetlive.com/KB/Article/0000788

http://www.linux-france.org/prj/pop2imap/

http://home.arcor.de/armin.diehl/imapcopy/imapcopy.html

IMAPcopy is a small utility that will help you migrate from one IMAP e-mail message store to a another one. I generally try to use this utility from the command line of one of the servers involved in the transfer in order to minimize traffic and time. You can copy many users at once, if you wish.

IMAPCopy doesn't really require any installation.

wget http://home.arcor.de/armin.diehl/imapcopy/imapcopy.tar.gz
tar -xzvf imapcopy.tar.gz
cd imapcopy

Edit the configuration file for each job:

vi  ImapCopy.cfg

Make it look like:

SourceServer <source-server>
SourcePort 143
DestServer <destination-server>
DestPort 143

# CreateEmptyFolders

skipfolder INBOX.Trash
skipfolder INBOX.Sent
skipfolder "INBOX.Deleted Items"
skipfolder "INBOX.Sent Items"
skipfolder "INBOX.Junk E-Mail"
skipfolder Trash
skipfolder Sent
skipfolder "Sent Items"
skipfolder "Junk E-Mail"
skipfolder "Deleted Items"

DenyFlags "\Recent"

#        SrcUser       SrcPasswd           DestUser        DestPasswd
#        ==========    =============       =============   ==============
#Copy    "bar"         "barsrcpw"          "bar"           "bardestpw"
Copy     "username"    "password"          "newuser"       "newpassword"

Now verify that all users and passwords are correct:

./imapcopy -t

Then transfer the messages if all is well:

./imapcopy

http://wiki.zimbra.com/wiki/Guide_to_imapsync

http://www.howtoforge.com/how-to-migrate-mailboxes-between-imap-servers-with-imapsync

http://www.linux-france.org/prj/imapsync/

Imapsync is a great tool for migrating IMAP message stores from one server to another.

• no duplicates
• restart failed copy
• command line - no GUI required
• requires Perl and various modules
• preferably install on new mail server to minimize network transfers

https://gist.github.com/nosmall/1306659d714e2c07810ba2cfc511fee5

https://github.com/imapsync/imapsync/blob/master/INSTALL.d/INSTALL.Ubuntu.txt

See also Configure EPEL Repository

yum install imapsync --enablerepo=epel

Imapsync is also available from the RPMForge repository if you already have that repo configured.

man imapsync
imapsync --help

Migrate from 'host1' to 'host2':

imapsync \
--buffersize 8192000 \
--noauthmd5 \
--host1 old.mail.server \
--user1 olduser \
--password1 oldpassword \
--host2 localhost \
--user2 newuser \
--password2 newpassword

The delete2 option deletes messages from the destination that are no longer on the source.

You must Enable clear text login in Zimbra and restart the server:

Zimbra Administration → Configure → Global Settings → IMAP

imapsync --buffersize 8192000 --nosyncacls --subscribe --syncinternaldates --addheader --delete2 \
   --host1 old.server.tld --ssl1 --port1 993 \
   --user1 oldusername --password1 'oldpassword' \
   --host2 new.server.tld --ssl2 --port2 993 \
   --user2 newemailaddr --password2 'newpassword'

1. For mail messages
   • Use imapsync
2. For contacts
   • Use Zimbra Web Client (ZWC)
   • Preferences → Import/Export → Outloook Contacts → Choose Source Contacts folder(s) → Export
3. For calendars
   • Use ZWC
   • Preferences → Import/Export → Calendar → Select Calendar folder(s) → Export

In Outlook 2013 with Exchange Account configured:

1. File → Open and Export → Import/Export → Import from another program or file → Comma Separated Values
2. Browse to csv file, Next → choose duplicates option, Next → Select Contacts folder, Next → Map Custom Fields
3. In the left pane scroll about halfway down to “EmailAddress”, In the right pane scroll about halfway down to E-mail click + sign E-mail Address.
4. In left pane drag EmailAddress and drop in right pane on E-mail Address, OK → Finish