Help with 1) mailserver setup - Ubuntu/Dovecot/Postfix and 2) Nutch/Solr

Hi. This is an initial project that I would see as a possible foundation for an ongoing relationship for advice about Linux and network questions. You are welcome to bid on just some of those points if you have some of the skills but not those required to do the whole thing. For now there are two parts: Mailserver configuration ----------------------------------- I have set up a mailserver on a VPS with a secondary server (also on a VPS) as backup. The main server runs Centos 6, and the backup runs Ubuntu 12. I am running into some difficulties, mostly relating to the secondary server, and the interactions with the primary. Currently the problems are as follows:- 1) I cannot SSH without a password from one machine to the other (both ways don't work). I have tried generating a key, and checking the [login to view URL] files on both machine. SSH with password works fine. But I cannot get it to work without password and need some help getting there. 2) I would like to run the latest stable version of Postfix (2.2.10) with Postgresql and SASL support and recompiled this on my Centos machine. I am having trouble figuring out how to do this on the Ubuntu machine. This should be a pretty simple question if you know how to do it. I need to figure out which repository address has latest sources and download/build from that site and then tell Ubuntu not to update the package. The problem is I don't know how to get the dependencies/libraries/development packages. 3) Dovecot incorporates full text search using Solr but in recent versions it does not optimize or commit to Solr. I would like to set up a cron job to regularly perform these functions. Pretty simple, but I don't know cron. 4) I would like to set up a fail-over DNS (using a non-commercial solution running on a third linux box) so that if my main IMAP and/or SMTP servers go down, my own email clients and mailers from the outside world are redirected automatically to the backup machine. 5) I would like help to check I have covered the key security vulnerabilities for each server. 6) I have dovecot replication working via doveadm, but not via dsync server. Part of the problem is not having ssh without password, but I am also not sure which users to run various processes as. I have a vmail user and the regular system mail user. I would like help tweaking the configuration for doveadm. 7) I would like to know what the best tools are to monitor my servers locally (on Windows machine) and on ipad/android, via SMS and email (free solutions), and I would like someone to act as a backup to take care of any problems in case I am travelling or don't have time to fix them. 8)I would like to setup dovecot to refilter my existing mail through sieve (described clearly on [login to view URL]). Sieve is up and running already. 9) Thunderbird managesieve extension won't talk to managesieve - I need some help figuring out why. Nutch/Solr ---------------- 10) I have a lot of PDFs on my local machine (thousands) of scanned books and other documents that I would like to index and search using Nutch/Solr/Tika. Also, in the longer-term, I would like to start crawling, downloading content, and indexing various web sites of interest in my industry. I have all of these set up - Solr and Tika more than Nutch. I decided to run Nutch on a VMLINUX box on my Windows machine at home (where the documents reside) since it is a pain messing around with Cygwin. It's almost working, but not quite - and I need some help configuring Nutch, and possibly the Solr schema. I may need some help writing a search front-end in whatever makes most sense (I know Solr has some templates that should be easy to modify). 11) I am really stuck on finding a good way to OCR maybe 3,000 PDFs. I have Acrobat Pro, but this is very slow and not so stable when operating in batch mode (and it often stops at a dialogue box). Please bid on the parts you can help with showing itemized prices. Let me know if any questions.