stat=Deferred: Connection reset by smtp.zoho.com. Error

stat=Deferred: Connection reset by smtp.zoho.com. Error

Hi, 

Linux centos 7 server fails to out emails. I use the below command to send out emails.

  1. echo "hi" | mail -s mohtashim@digiklug.com

My /var/logs/maillog shows the following corresponding error msg


Sep 12 19:23:57 Development_Digiklug sendmail[9280]: v8CJL5mo009278: to=< mohtashim@digiklug.com>, ctladdr=< root@dev.digiklug.com> (0/0), delay=00:02:52, xdelay=00:02:52, mailer=relay, pri=120448, relay=smtp.zoho.com. [8.40.222.118], dsn=4.0.0, stat=Deferred: Connection reset by smtp.zoho.com.
My SMTP is listening on the following ports and i m also able to telnet to these from a different server.

  1.  netstat -ltnp | grep sendmail
  2. tcp        0      0 0.0.0.0:587             0.0.0.0:*               LISTEN      9206/sendmail: acce
  3. tcp        0      0 0.0.0.0:465             0.0.0.0:*               LISTEN      9206/sendmail: acce
  4. tcp        0      0 0.0.0.0:25              0.0.0.0:*               LISTEN      9206/sendmail: acce

Here is the Authorization details:

  1. more /etc/mail/auth/authinfo
  2. AuthInfo:smtp.zoho.com "U:mohtashim@digiklug.com" "I:mohtashim@digiklug.com" "P:xxxxxxxxxx" "M:PLAIN DIGEST-MD5"
Below are the changes to the default sendmail.mc configuration that i did.

  1. # Adding config for zoho #
  2. define(`SMART_HOST',`[smtp.zoho.com]')dnl
  3. define(`RELAY_MAILER_ARGS', `TCP $h 465')dnl
  4. define(`confAUTH_OPTIONS', `A p')dnl
  5. TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
  6. define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl

  8. define(`confCACERT_PATH', `/etc/pki/tls/certs')dnl
  9. define(`confCACERT', `/etc/pki/tls/certs/ca-bundle.crt')dnl
  10. define(`confSERVER_CERT', `/etc/pki/tls/certs/sendmail.pem')dnl
  11. define(`confSERVER_KEY', `/etc/pki/tls/certs/sendmail.pem')dnl
  12. FEATURE(`authinfo',`hash /etc/mail/auth/authinfo')dnl

  14. DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea')dnl
  15. DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s')dnl
  16. # End config for zoho #

  18. MAILER(smtp)dnl
  19. MAILER(procmail)dnl
  20. dnl MAILER(cyrusv2)dnl
Attaching the entire sendmail.mc configuration file here: Click to DownLoad

Kindly help debug the issue.