Migrate mail from one server to another with imapsync

Have you been in the situation where you needed to move everyone’s mail from one provider to another? It’s a pain to do using the mail client one at a time, but with this guide, you’ll be able to create a csv with everyone’s info and run one command to fire it all off. All you need is a Linux machine to do it.

First, you’ll need to install the epel repo (skip if you already have it):

CentOS 5 (as root):

wget http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
wget http://rpms.famillecollet.com/enterprise/remi-release-5.rpm
rpm -Uvh remi-release-5*.rpm epel-release-5*.rpm

wget http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm

wget http://rpms.famillecollet.com/enterprise/remi-release-5.rpm

rpm -Uvh remi-release-5*.rpm epel-release-5*.rpm

CentOS 6 (as root):

wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm

wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm

rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm

Now, use yum to install imapsync. It will automagically install all of the deps.

yum install imapsync

1	yum install imapsync

Now that it’s installed, let’s print out the help file and take a look at all of the usefulness of imapsync:

[root@backup BACKUP]# imapsync --help

usage: /usr/bin/imapsync [options]

Several options are mandatory. 

--dry                  : Makes imapsync doing nothing, just print what would 
                         be done without --dry.

--host1       <string> : Source or "from" imap server. Mandatory.
--port1       <int>    : Port to connect on host1. Default is 143.
--user1       <string> : User to login on host1. Mandatory.
--showpasswords        : Shows passwords on output instead of "MASKED".
                         Useful to restart a complete run by just reading a log.
--password1   <string> : Password for the user1.
--host2       <string> : "destination" imap server. Mandatory.
--port2       <int>    : Port to connect on host2. Default is 143.
--user2       <string> : User to login on host2. Mandatory.
--password2   <string> : Password for the user2.

--passfile1   <string> : Password file for the user1. It must contain the 
                         password on the first line. This option avoids to show 
                         the password on the command line like --password1 does.
--passfile2   <string> : Password file for the user2. Contains the password.
--domain1     <string> : Domain on host1 (NTLM authentication).
--domain2     <string> : Domain on host2 (NTLM authentication).
--authuser1   <string> : User to auth with on host1 (admin user). 
                         Avoid using --authmech1 SOMETHING with --authuser1.
--authuser2   <string> : User to auth with on host2 (admin user).
--proxyauth1           : Use proxyauth on host1. Requires --authuser1.
                         Required by Sun/iPlanet/Netscape IMAP servers to
                         be able to use an administrative user.
--proxyauth2           : Use proxyauth on host2. Requires --authuser2.
                         Required by Sun/iPlanet/Netscape IMAP servers to
                         be able to use an administrative user

--authmd51             : Use MD5 authentification for host1.
--authmd52             : Use MD5 authentification for host2.
--authmech1   <string> : Auth mechanism to use with host1:
                         PLAIN, LOGIN, CRAM-MD5 etc. Use UPPERCASE.
--authmech2   <string> : Auth mechanism to use with host2. See --authmech1
--ssl1                 : Use an SSL connection on host1.
--ssl2                 : Use an SSL connection on host2.
--tls1                 : Use an TLS connection on host1.
--tls2                 : Use an TLS connection on host2.
--timeout    <int>     : Connections timeout in seconds. Default is 120.
                         0 means no timeout.

--folder      <string> : Sync this folder.
--folder      <string> : and this one, etc.
--folderrec   <string> : Sync this folder recursively.
--folderrec   <string> : and this one, etc.
--include     <regex>  : Sync folders matching this regular expression
                         Blancs like in "foo bar" have to be written "foo\ bar"
--include     <regex>  : or this one, etc.
                         in case both --include --exclude options are
                         use, include is done before.
--exclude     <regex>  : Skips folders matching this regular expression
                         Several folders to avoid:
			  --exclude 'fold1|fold2|f3' skips fold1, fold2 and f3.
--exclude     <regex>  : or this one, etc.
--regextrans2 <regex>  : Apply the whole regex to each destination folders.
--regextrans2 <regex>  : and this one. etc.
                         When you play with the --regextrans2 option, first
                         add also the safe options --dry --justfolders
                         Then, when happy, remove --dry, remove --justfolders.
                         Have in mind that --regextrans2 is applied after prefix 
                         and separator inversion.

--tmpdir      <string> : Where to store temporary files and subdirectories.
                         Will be created if it doesn't exist.
			 Default is system specific, Unix is /tmp but
                         it's often small and deleted at reboot.
                         --tmpdir /var/tmp should be better.
--pidfile     <string> : The file where imapsync pid is written.
--pidfilelocking       : Abort if pidfile already exists. Usefull to avoid 
                         concurrent transfers on the same mailbox.

--prefix1     <string> : Remove prefix to all destination folders 
                         (usually INBOX. or INBOX/ or an empty string "")
                         you have to use --prefix1 if host1 imap server
                         does not have NAMESPACE capability, all other
                         cases are bad.
--prefix2     <string> : Add prefix to all host2 folders. See --prefix1
--sep1        <string> : Host1 separator in case NAMESPACE is not supported.
--sep2        <string> : Host2 separator in case NAMESPACE is not supported.

--regexmess   <regex>  : Apply the whole regex to each message before transfer.
                         Example: 's/\000/ /g' # to replace null by space.
--regexmess   <regex>  : and this one.
--regexmess   <regex>  : and this one, etc.
--regexflag   <regex>  : Apply the whole regex to each flags list.
                         Example: 's/"Junk"//g' # to remove "Junk" flag.
--regexflag   <regex>  : and this one, etc.

--delete               : Deletes messages on host1 server after a successful 
                         transfer. Option --delete has the following behavior: 
                         it marks messages as deleted with the IMAP flag 
                         \Deleted, then messages are really deleted with an 
                         EXPUNGE IMAP command.
--delete2              : Delete messages in host2 that are not in
                         host1 server. Useful for backup or pre-sync.
--delete2duplicates    : Delete messages in host2 that are duplicates.
                         Works only without --useuid since duplicates are 
                         detected with header part of each message.
--delete2folders       : Delete folders in host2 that are not in host1 server. 
                         For safety, first try it like this (it is safe):
			 --delete2folders --dry --justfolders --nofoldersizes
--delete2foldersonly   <regex>: Deleted only folders matching regex.
--delete2foldersbutnot <regex>: Do not delete folders matching regex.
                         Example: --delete2foldersbutnot "/Tasks|Contacts|Foo/"
--noexpunge            : Do not expunge messages on host1.
                         Expunge really deletes messages marked deleted.
                         Expunge is made at the beginning, on host1 only. 
                         Newly transferred messages are also expunged if 
			 option --delete is given.
                         No expunge is done on host2 account (unless --expunge2)
--expunge1             : Expunge messages on host1 after messages transfer.
--expunge2             : Expunge messages on host2 after messages transfer.
--uidexpunge2          : uidexpunge messages on the host2 account
                         that are not on the host1 account, requires --delete2

--syncinternaldates    : Sets the internal dates on host2 same as host1.
                         Turned on by default. Internal date is the date
			 a message arrived on a host (mtime).
--idatefromheader      : Sets the internal dates on host2 same as the 
                         "Date:" headers.

--maxsize     <int>    : Skip messages larger  (or equal) than <int> bytes
--minsize     <int>    : Skip messages smaller (or equal) than <int> bytes
--maxage      <int>    : Skip messages older than <int> days.
                         final stats (skipped) don't count older messages
			 see also --minage
--minage      <int>    : Skip messages newer than <int> days.
                         final stats (skipped) don't count newer messages
                         You can do (+ are the messages selected):
                         past|----maxage+++++++++++++++>now
                         past|+++++++++++++++minage---->now
                         past|----maxage+++++minage---->now (intersection)
                         past|++++minage-----maxage++++>now (union)

--search      <string> : Selects only messages returned by this IMAP SEARCH 
                         command. Applied on both sides.
--search1     <string> : Same as --search for selecting host1 messages only.
--search2     <string> : Same as --search for selecting host2 messages only.
                         --search CRIT equals --search1 CRIT --search2 CRIT

--exitwhenover   <int> : Stop syncing when total bytes transferred reached.
                         Gmail per day allows 2500000000 down 500000000 upload.

--maxlinelength <int>  : skip messages with line length longer than <int> bytes.
                         RFC 2822 says it must be no more than 1000 bytes.

--useheader   <string> : Use this header to compare messages on both sides.
                         Ex: Message-ID or Subject or Date.
--useheader   <string>   and this one, etc.

--subscribed           : Transfers subscribed folders.
--subscribe            : Subscribe to the folders transferred on the 
                         host2 that are subscribed on host1. On by default.
--subscribe_all        : Subscribe to the folders transferred on the 
                         host2 even if they are not subscribed on host1.

--nofoldersizes        : Do not calculate the size of each folder in bytes
                         and message counts. Default is to calculate them.
--nofoldersizesatend   : Do not calculate the size of each folder in bytes
                         and message counts at the end. Default is on.
--justfoldersizes      : Exit after having printed the folder sizes.

--syncacls             : Synchronises acls (Access Control Lists).
--nosyncacls           : Does not synchronize acls. This is the default.
                         Acls in IMAP are not standardized, be careful.

--usecache             : Use cache to speedup.
--nousecache           : Do not use cache. Caveat: --useuid --nousecache creates
                         duplicates on multiple runs.
--useuid               : Use uid instead of header as a criterium to recognize 
                         messages. Option --usecache is then implied unless 
                         --nousecache is used.  

--debug                : Debug mode.
--debugcontent         : Debug content of the messages transfered.
--debugflags           : Debug flags.
--debugimap1           : IMAP debug mode for host1. imap debug is very verbose.
--debugimap2           : IMAP debug mode for host2.
--debugimap            : IMAP debug mode for host1 and host2.

--version              : Print software version.
--noreleasecheck       : Do not check for new imapsync release (a http request).
--justconnect          : Just connect to both servers and print useful
                         information. Need only --host1 and --host2 options.
--justlogin            : Just login to both host1 and host2 with users 
                         credentials, then exit.
--justfolders          : Do only things about folders (ignore messages).

--help                 : print this help.

Example: to synchronize imap account "foo" on "imap.truc.org"
                    to  imap account "bar" on "imap.trac.org"
                    with foo password "secret1"
                    and  bar password "secret2"

/usr/bin/imapsync \
   --host1 imap.truc.org --user1 foo --password1 secret1 \
   --host2 imap.trac.org --user2 bar --password2 secret2

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[root@backup BACKUP]# imapsync --help

usage: /usr/bin/imapsync [options]

Several options are mandatory.

--dry : Makes imapsync doing nothing, just print what would

be done without --dry.

--host1 <string> : Source or "from" imap server. Mandatory.

--port1 <int> : Port to connect on host1. Default is 143.

--user1 <string> : User to login on host1. Mandatory.

--showpasswords : Shows passwords on output instead of "MASKED".

Useful to restart a complete run by just reading a log.

--password1 <string> : Password for the user1.

--host2 <string> : "destination" imap server. Mandatory.

--port2 <int> : Port to connect on host2. Default is 143.

--user2 <string> : User to login on host2. Mandatory.

--password2 <string> : Password for the user2.

--passfile1 <string> : Password file for the user1. It must contain the

password on the first line. This option avoids to show

the password on the command line like --password1 does.

--passfile2 <string> : Password file for the user2. Contains the password.

--domain1 <string> : Domain on host1 (NTLM authentication).

--domain2 <string> : Domain on host2 (NTLM authentication).

--authuser1 <string> : User to auth with on host1 (admin user).

Avoid using --authmech1 SOMETHING with --authuser1.

--authuser2 <string> : User to auth with on host2 (admin user).

--proxyauth1 : Use proxyauth on host1. Requires --authuser1.

Required by Sun/iPlanet/Netscape IMAP servers to

be able to use an administrative user.

--proxyauth2 : Use proxyauth on host2. Requires --authuser2.

Required by Sun/iPlanet/Netscape IMAP servers to

be able to use an administrative user

--authmd51 : Use MD5 authentification for host1.

--authmd52 : Use MD5 authentification for host2.

--authmech1 <string> : Auth mechanism to use with host1:

PLAIN, LOGIN, CRAM-MD5 etc. Use UPPERCASE.

--authmech2 <string> : Auth mechanism to use with host2. See --authmech1

--ssl1 : Use an SSL connection on host1.

--ssl2 : Use an SSL connection on host2.

--tls1 : Use an TLS connection on host1.

--tls2 : Use an TLS connection on host2.

--timeout <int> : Connections timeout in seconds. Default is 120.

0 means no timeout.

--folder <string> : Sync this folder.

--folder <string> : and this one, etc.

--folderrec <string> : Sync this folder recursively.

--folderrec <string> : and this one, etc.

--include <regex> : Sync folders matching this regular expression

Blancs like in "foo bar" have to be written "foo\ bar"

--include <regex> : or this one, etc.

in case both --include --exclude options are

use, include is done before.

--exclude <regex> : Skips folders matching this regular expression

Several folders to avoid:

--exclude 'fold1|fold2|f3' skips fold1, fold2 and f3.

--exclude <regex> : or this one, etc.

--regextrans2 <regex> : Apply the whole regex to each destination folders.

--regextrans2 <regex> : and this one. etc.

When you play with the --regextrans2 option, first

add also the safe options --dry --justfolders

Then, when happy, remove --dry, remove --justfolders.

Have in mind that --regextrans2 is applied after prefix

and separator inversion.

--tmpdir <string> : Where to store temporary files and subdirectories.

Will be created if it doesn't exist.

Default is system specific, Unix is /tmp but

it's often small and deleted at reboot.

--tmpdir /var/tmp should be better.

--pidfile <string> : The file where imapsync pid is written.

--pidfilelocking : Abort if pidfile already exists. Usefull to avoid

concurrent transfers on the same mailbox.

--prefix1 <string> : Remove prefix to all destination folders

(usually INBOX. or INBOX/ or an empty string "")

you have to use --prefix1 if host1 imap server

does not have NAMESPACE capability, all other

cases are bad.

--prefix2 <string> : Add prefix to all host2 folders. See --prefix1

--sep1 <string> : Host1 separator in case NAMESPACE is not supported.

--sep2 <string> : Host2 separator in case NAMESPACE is not supported.

--regexmess <regex> : Apply the whole regex to each message before transfer.

Example: 's/\000/ /g' # to replace null by space.

--regexmess <regex> : and this one.

--regexmess <regex> : and this one, etc.

--regexflag <regex> : Apply the whole regex to each flags list.

Example: 's/"Junk"//g' # to remove "Junk" flag.

--regexflag <regex> : and this one, etc.

--delete : Deletes messages on host1 server after a successful

transfer. Option --delete has the following behavior:

it marks messages as deleted with the IMAP flag

\Deleted, then messages are really deleted with an

EXPUNGE IMAP command.

--delete2 : Delete messages in host2 that are not in

host1 server. Useful for backup or pre-sync.

--delete2duplicates : Delete messages in host2 that are duplicates.

Works only without --useuid since duplicates are

detected with header part of each message.

--delete2folders : Delete folders in host2 that are not in host1 server.

For safety, first try it like this (it is safe):

--delete2folders --dry --justfolders --nofoldersizes

--delete2foldersonly <regex>: Deleted only folders matching regex.

--delete2foldersbutnot <regex>: Do not delete folders matching regex.

Example: --delete2foldersbutnot "/Tasks|Contacts|Foo/"

--noexpunge : Do not expunge messages on host1.

Expunge really deletes messages marked deleted.

Expunge is made at the beginning, on host1 only.

Newly transferred messages are also expunged if

option --delete is given.

No expunge is done on host2 account (unless --expunge2)

--expunge1 : Expunge messages on host1 after messages transfer.

--expunge2 : Expunge messages on host2 after messages transfer.

--uidexpunge2 : uidexpunge messages on the host2 account

that are not on the host1 account, requires --delete2

--syncinternaldates : Sets the internal dates on host2 same as host1.

Turned on by default. Internal date is the date

a message arrived on a host (mtime).

--idatefromheader : Sets the internal dates on host2 same as the

"Date:" headers.

--maxsize <int> : Skip messages larger (or equal) than <int> bytes

--minsize <int> : Skip messages smaller (or equal) than <int> bytes

--maxage <int> : Skip messages older than <int> days.

final stats (skipped) don't count older messages

see also --minage

--minage <int> : Skip messages newer than <int> days.

final stats (skipped) don't count newer messages

You can do (+ are the messages selected):

past|----maxage+++++++++++++++>now

past|+++++++++++++++minage---->now

past|----maxage+++++minage---->now (intersection)

past|++++minage-----maxage++++>now (union)

--search <string> : Selects only messages returned by this IMAP SEARCH

command. Applied on both sides.

--search1 <string> : Same as --search for selecting host1 messages only.

--search2 <string> : Same as --search for selecting host2 messages only.

--search CRIT equals --search1 CRIT --search2 CRIT

--exitwhenover <int> : Stop syncing when total bytes transferred reached.

Gmail per day allows 2500000000 down 500000000 upload.

--maxlinelength <int> : skip messages with line length longer than <int> bytes.

RFC 2822 says it must be no more than 1000 bytes.

--useheader <string> : Use this header to compare messages on both sides.

Ex: Message-ID or Subject or Date.

--useheader <string> and this one, etc.

--subscribed : Transfers subscribed folders.

--subscribe : Subscribe to the folders transferred on the

host2 that are subscribed on host1. On by default.

--subscribe_all : Subscribe to the folders transferred on the

host2 even if they are not subscribed on host1.

--nofoldersizes : Do not calculate the size of each folder in bytes

and message counts. Default is to calculate them.

--nofoldersizesatend : Do not calculate the size of each folder in bytes

and message counts at the end. Default is on.

--justfoldersizes : Exit after having printed the folder sizes.

--syncacls : Synchronises acls (Access Control Lists).

--nosyncacls : Does not synchronize acls. This is the default.

Acls in IMAP are not standardized, be careful.

--usecache : Use cache to speedup.

--nousecache : Do not use cache. Caveat: --useuid --nousecache creates

duplicates on multiple runs.

--useuid : Use uid instead of header as a criterium to recognize

messages. Option --usecache is then implied unless

--nousecache is used.

--debug : Debug mode.

--debugcontent : Debug content of the messages transfered.

--debugflags : Debug flags.

--debugimap1 : IMAP debug mode for host1. imap debug is very verbose.

--debugimap2 : IMAP debug mode for host2.

--debugimap : IMAP debug mode for host1 and host2.

--version : Print software version.

--noreleasecheck : Do not check for new imapsync release (a http request).

--justconnect : Just connect to both servers and print useful

information. Need only --host1 and --host2 options.

--justlogin : Just login to both host1 and host2 with users

credentials, then exit.

--justfolders : Do only things about folders (ignore messages).

--help : print this help.

Example: to synchronize imap account "foo" on "imap.truc.org"

to imap account "bar" on "imap.trac.org"

with foo password "secret1"

and bar password "secret2"

/usr/bin/imapsync \

--host1 imap.truc.org --user1 foo --password1 secret1 \

--host2 imap.trac.org --user2 bar --password2 secret2

Now let’s get to business and start a sync. Let’s just do one user first before we jump into doing multiple at once.

Our info for this task:
Old: server=old.mailserver.com, user=test@domain.com, pass=mypasswd
New: server=new.mailserver.com, user=test@domain.com, pass=mypasswd

Here’s the command:

/usr/bin/imapsync \
   --host1 old.mailserver.com --user1 test@domain.com --password1 mypasswd \
   --host2 new.mailserver.com --user2 test@domain.com --password2 mypasswd

/usr/bin/imapsync \

--host1 old.mailserver.com --user1 test@domain.com --password1 mypasswd \

--host2 new.mailserver.com --user2 test@domain.com --password2 mypasswd

Let’s migrate multiple people at once now!

Create a file full of info called ‘file.txt’. An example is here

test@domain.com;mypasswd;test@domain.com;mypasswd
test2@domain.com;hispasswd;test2@domain.com;hispasswd
test3@domain.com;herpasswd;test3@domain.com;herpasswd

test@domain.com;mypasswd;test@domain.com;mypasswd

test2@domain.com;hispasswd;test2@domain.com;hispasswd

test3@domain.com;herpasswd;test3@domain.com;herpasswd

Now, paste this into sync_loop_unix.sh

#!/bin/sh
#
# $Id: sync_loop_unix.sh,v 1.2 2012/12/23 08:02:46 gilles Exp gilles $

# Example for imapsync massive migration on Unix systems.
# 
# Data is supposed to be in file.txt in the following format
#user001_1;password001_1;user001_2;password001_2
#...
# Separator is character semi-colon ; it can be changed by any character changing IFS=';'
# Each data line contains 4 columns, columns are parameters for --user1 --password1 --user2 --password2
#
# Replace "imap.side1.org" and "imap.side2.org" with your own hostname values

# This loop will also create a log file called LOG/log_${u2}_$NOW.txt for each account transfer
# where u2 is just a variable containing the user2 account name, and NOW is the current date_time

mkdir -p LOG

{ while IFS=';' read  u1 p1 u2 p2
    do 
         { echo "$u1" | egrep "^#" ; } > /dev/null && continue
         NOW=`date +%Y_%m_%d_%H_%M_%S` 
         echo syncing to user "$u2"
         imapsync --host1 imap.side1.org --user1 "$u1" --password1 "$p1" \
                  --host2 imap.side2.org --user2 "$u2" --password2 "$p2" \
                  > LOG/log_${u2}_$NOW.txt 2>&1
    done 
} < file.txt

#!/bin/sh

# $Id: sync_loop_unix.sh,v 1.2 2012/12/23 08:02:46 gilles Exp gilles $

# Example for imapsync massive migration on Unix systems.

# Data is supposed to be in file.txt in the following format

#user001_1;password001_1;user001_2;password001_2

#...

# Separator is character semi-colon ; it can be changed by any character changing IFS=';'

# Each data line contains 4 columns, columns are parameters for --user1 --password1 --user2 --password2

# Replace "imap.side1.org" and "imap.side2.org" with your own hostname values

# This loop will also create a log file called LOG/log_${u2}_$NOW.txt for each account transfer

# where u2 is just a variable containing the user2 account name, and NOW is the current date_time

mkdir -p LOG

{ while IFS=';' read u1 p1 u2 p2

{ echo "$u1" | egrep "^#" ; } > /dev/null && continue

NOW=`date +%Y_%m_%d_%H_%M_%S`

echo syncing to user "$u2"

imapsync --host1 imap.side1.org --user1 "$u1" --password1 "$p1" \

--host2 imap.side2.org --user2 "$u2" --password2 "$p2" \

> LOG/log_${u2}_$NOW.txt 2>&1

done

} < file.txt

(Make sure to change the hosts in the sync_loop_unix.sh file)

Make it executable:

chmod +x sync_loop_unix.sh

1	chmod +x sync_loop_unix.sh

Now run it!

./sync_loop_unix.sh

1	./sync_loop_unix.sh

You can add as many accounts as you want in the csv file.

Read more about imapsync on their official page: http://imapsync.lamiral.info/

2 responses to Migrate mail from one server to another with imapsync

Godislife January 11, 2015 at 9:58 pm

thanks for you tutorial!

Michel February 16, 2015 at 3:50 am

Thank you very much!

Hary
Many Thanks Brother
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Migrate mail from one server to another with imapsync

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