Hello again,
thanks to guys at Zimbra for providing some help to figure all the missing things out. First of all you need zimbraDataSourceFolderId value. You can get it by executing something like this: Code:
~]$ zmmailbox -z -m "$email" createFolder -F u /"$exmserv"`
$email is email and $exmserv is external mail server URL (as folder name). This will create folder and return folder id.
To add bulk external accounts from CLI I wrote quick and dirty bash script. There is also requirement for userlist.txt - csv file with following fields:
Code:
email,password,display name,givenname,secondname
This script reads file line by line, splits line into fields then creates folder and adds external account to it. If you want to use this script then correct it to your needs e.g. change or add mail server, add SSL support, change user name etc. 
Code:
#!/bin/bash
#addexmail.sh script by akovonklap (c). Add external accounts from CLI
exec 3< userlist.txt
while read <&3
do
email=`echo "$REPLY"| awk -F, '{print $1}'`
passwd=`echo "$REPLY"| awk -F, '{print $2}'`
dispname=`echo "$REPLY"| awk -F, '{print $3}'`
gname=`echo "$REPLY"| awk -F, '{print $4}'`
sn=`echo "$REPLY"| awk -F, '{print $5}'`
exmserv="mail.example.com" #External mail server
user=`echo "$email"|awk -F@ '{print $1}'`
zmmailbox -z -m "$email" createFolder -F u /"$exmserv" > /tmp/$exmserv".txt"
foldid=`cat /tmp/$exmserv".txt"`
zmprov cds "$email" imap "$exmserv" \
objectClass zimbraDataSource \
objectClass zimbraImapDataSource \
zimbraPrefFromDisplay "$dispname" \
zimbraPrefReplyToDisplay "$dispname" \
zimbraDataSourceName "$exmserv" \
zimbraDataSourceFolderId "$foldid" \
zimbraDataSourceType imap \
zimbraDataSourceConnectionType cleartext \
zimbraDataSourceEnabled TRUE \
zimbraDataSourceUseAddressForForwardReply TRUE \
zimbraDataSourceHost "$exmserv" \
zimbraDataSourceUsername "$user" \
zimbraDataSourcePassword "$passwd" \
zimbraPrefFromAddress "$email" \
zimbraDataSourceEmailAddress "$email" \
zimbraPrefReplyToAddress "$email" \
zimbraDataSourcePollingInterval 9m \
zimbraDataSourcePort 143 \
done
rm -f /tmp/$exmserv".txt"
exit 0 I Hope this will help to someone..