Mail restore issue

[kondaiahn]

Hi,
I have installed Zmbkpose-rewrite_proposal_v2.0 on my zimbra open source 8.6. Incremental and full backup are happening properly. After taking full backup, I have deleted some of the mails and tries to restore from the full backup. I have used
zmbkpose -r -a abc@domain.com
for restoration. But it is displaying the following error and no mails are getting retried.

zmbkpose -r -a abc@domain.com
2017-03-23 10:58:38 DEBUG: Testing ldapserver ldap://XX.X.X.XXX:389, using user uid=zimbra,cn=admins,cn=zimbra
2017-03-23 10:58:38 DEBUG: abc@domain.com - Using ldap data from backup /opt/zimbra/backup/domain.com/abc/20170323100732:FULL.tar
2017-03-23 10:58:38 DEBUG: abc@domain.com - Ldap restore started
2017-03-23 10:58:38 DEBUG: abc@domain.com - Adding ldap entry: zimbraSignatureName=External
ldapadd: invalid format (line 5) entry: "zimbraSignatureName=External email,uid=abc,ou=people,dc=domain,dc=com"

Any help in this regard is highly appreciated.
Thanks in advance.