I have 4 postfix servers & 1 ldap+webmail server . I am not able to login it shows error " Connection dropped by IMAP server"
My maillogs showing that postfix servers are not able to authenticate with ldapserver

tail -f /var/log/maillog
Sep 30 13:12:02 mailsrv1 postfix/master[32421]: warning: process /usr/libexec/postfix/trivial-rewrite pid 18185 exit status 1
Sep 30 13:12:04 mailsrv1 postfix/trivial-rewrite[18274]: warning: dict_ldap_connect: Unable to bind to server ldap://MailWebSrv1:389 as cn=manager,dc=nabardmail,dc=co,dc=in: -5 (Timed out)
Sep 30 13:12:04 mailsrv1 postfix/trivial-rewrite[18274]: fatal: ldap:/etc/postfix/ldap-aliases.cf(0,lock|fold_fix): table lookup problem
Sep 30 13:12:05 mailsrv1 authdaemond: using search filter: (&(objectClass=posixAccount)(mail=SLAReport@wipro.dccbindia.co.in))
Sep 30 13:12:05 mailsrv1 authdaemond: using search filter: (&(objectClass=posixAccount)(mail=l2hlpdsk.maha@wipro.dccbindia.co.in))
Sep 30 13:12:05 mailsrv1 authdaemond: using search filter: (&(objectClass=posixAccount)(mail=samruthau@wipro.dccbindia.co.in))
Sep 30 13:12:05 mailsrv1 postfix/smtpd[6207]: warning: problem talking to service rewrite: Connection reset by peer
Sep 30 13:12:05 mailsrv1 postfix/smtpd[11782]: warning: problem talking to service rewrite: Success
Sep 30 13:12:05 mailsrv1 postfix/master[32421]: warning: process /usr/libexec/postfix/trivial-rewrite pid 18274 exit status 1
Sep 30 13:12:07 mailsrv1 postfix/smtpd[12769]: connect from unknown[10.128.17.222]
Sep 30 13:12:45 mailsrv1 authdaemond: ldap_search_st() failed
Sep 30 13:12:45 mailsrv1 authdaemond: ldap_search_st() failed
Sep 30 13:12:45 mailsrv1 authdaemond: selected ldap protocol version 3
Sep 30 13:12:45 mailsrv1 authdaemond: binding to LDAP server as DN 'cn=Manager, dc=nabardmail, dc=co, dc=in', password 'wipro@123'
Sep 30 13:12:45 mailsrv1 authdaemond: selected ldap protocol version 3
Sep 30 13:12:45 mailsrv1 authdaemond: binding to LDAP server as DN 'cn=Manager, dc=nabardmail, dc=co, dc=in', password 'wipro@123'
Sep 30 13:12:45 mailsrv1 postfix/trivial-rewrite[18651]: warning: dict_ldap_lookup: Search error -5: Timed out
Sep 30 13:12:45 mailsrv1 postfix/trivial-rewrite[18651]: fatal: ldap:/etc/postfix/ldap-aliases.cf(0,lock|fold_fix): table lookup problem
Sep 30 13:12:45 mailsrv1 authdaemond: ldap_search_st() failed
Sep 30 13:12:45 mailsrv1 authdaemond: authldap: TEMPFAIL - no more modules will be tried
Sep 30 13:12:45 mailsrv1 postfix/trivial-rewrite[19148]: warning: dict_ldap_lookup: Search error -5: Timed out
Sep 30 13:12:45 mailsrv1 postfix/trivial-rewrite[19148]: fatal: ldap:/etc/postfix/ldap-aliases.cf(0,lock|fold_fix): table lookup problem
Sep 30 13:12:46 mailsrv1 postfix/smtpd[12620]: warning: problem talking to service rewrite: Connection reset by peer
Sep 30 13:12:46 mailsrv1 postfix/smtpd[12773]: warning: problem talking to service rewrite: Success
Sep 30 13:12:46 mailsrv1 postfix/master[32421]: warning: process /usr/libexec/postfix/trivial-rewrite pid 18651 exit status 1
Sep 30 13:12:46 mailsrv1 postfix/smtpd[12771]: warning: problem talking to service rewrite: Success
Sep 30 13:12:46 mailsrv1 postfix/smtpd[12772]: warning: problem talking to service rewrite: Connection reset by peer
Sep 30 13:12:46 mailsrv1 postfix/master[32421]: warning: process /usr/libexec/postfix/trivial-rewrite pid 19148 exit status 1
Sep 30 13:12:46 mailsrv1 authdaemond: using search filter: (&(objectClass=posixAccount)(mail=l2hlpdsk.maha@wipro.dccbindia.co.in))
Sep 30 13:12:46 mailsrv1 authdaemond: using search filter: (&(objectClass=posixAccount)(mail=SLAReport@wipro.dccbindia.co.in))

I am new to this, please ask if any other detail require..please help

Seems ldap is not running. Can you check the listening ports by issuing one of these and see if anything is on port 389?

ss -4tlna
netstat -tlnpa | grep ':389'
lsof :389

Your other thread for this EXACT SAME ISSUE was already quoted by descendant_command. You were asked questions in that other thread, never came back to it, and didn't answer them. What do you expect people to tell you??? Also, you've now been working on this for A SOLID MONTH...have you made no progress AT ALL??? Did you not find out any answers to the questions you were asked previously???