that worked without trouble but didnt fix the problem for me at least. my zimbra log now shows this
Mar 9 14:09:54 mail postfix/smtpd[31353]: lost connection after STARTTLS from c-67-169-127-128.hsd1.ca.comcast.net[67.169.127.128]
Mar 9 14:13:44 mail postfix/smtpd[22605]: warning: TLS library problem: 22605:error:0906D06C:PEM routines:PEM_read_bio:no start line
em_lib.c:632:Expecting: CERTIFICATE:
Mar 9 14:13:44 mail postfix/smtpd[22605]: warning: TLS library problem: 22605:error:140DC009:SSL routines:SSL_CTX_use_certificate_chain_file:PEM lib:ssl_rsa.c:765:
Mar 9 14:15:13 mail postfix/smtpd[11729]: lost connection after STARTTLS from c-67-169-127-128.hsd1.ca.comcast.net[67.169.127.128]
client shows same error as before