Redmine

Hello everyone.

I am running Redmine 2.3.3.stable on my Debian server. I am trying to make it fetch the incoming emails from an IMAP server. The problem is, that I have to connect to it using SSL (the IMAP server doesn't allow plaintext authentication on non-secure connection, this can't be changed). I thought that ssl=1 would be just fine, but what I am getting is

OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=unknown state: unknown protocol

Is there anything I can do to get rid of this error? Thanks a lot for any help.

RAILS_ENV=production script/about

Environment:
  Redmine version                2.3.3.stable
  Ruby version                   1.9.3-p194 (2012-04-20) [x86_64-linux]
  Rails version                  3.2.13
  Environment                    production
  Database adapter               Mysql2
Redmine plugins:
  project_section                0.0.1b
  redmine_contacts               3.2.17
  redmine_finance                1.0.5-light
  redmine_issue_checklist        2.0.5
  redmine_knowledgebase          2.3.0