When adding an external account to zimbra i receive "Error: Connection reset" message.

Zimbra log says -

May 11 01:46:34 zimbra postfix/smtpd[22342]: disconnect from ******.*****[]

No errors in SMTP log

IMAP log says -

May 11 11:51:36 ***** imapd: couriertls: connect: error:1408F10B:SSL routines:SSL3_GET_RECORD:wrong version number

I haven't selected "Use an encrypted connection (SSL) when accessing this server" so I am wondering what the deal is.

I can telnet from the zimbra host to smtp and imap ports.

New to zimbra. Appreciate any help.