I have a major issue in production environment. I am running zcs-8.0.2_GA_5569.FOSS on RHEL 6.2 64 bit. Multiserver environment with 1 LDAP Master, about 8 Mailstore servers, couple of MTA servers, Proxy for pop3/IMAP and Proxy for https.
The issue I am facing is that whenever a user tries to download a mail more than say 2MB via pop, the connection closes. All I can find in the /opt/zimbra/log/nginx.log is the following entry:

2013/02/21 23:53:12 [error] 17271#0: *725148 SSL_read() failed (SSL: error:1408F119:SSL routines:SSL3_GET_RECORD:decryption failed or bad record mac) while proxying and reading from upstream, client: IP.Addr.of.client using starttls, server:, login: "userid", upstream: IP.Addr.of.mailstoreserver:995 (IP.Addr.of.client:49956-IP.Addr.of.popproxy:110) <=> (IP.Addr.of.popproxy:34307-IP.Addr.of.mailstoreserver:995)
If I bypass proxy, and connect directly to the mailstore server, no issues. Everything works fine.

I can't find any relation between the above error and the problem we are facing. Any help is highly appreciated.