At the company I work at, I run several large high volume mass mailing servers that send million of messages a month (50 million last month). Here is what I recommend you do:
1) Get forward and reverse DNS setup and most importantly, the forward and reverse DNS information must match.
2) Set up and use DKIM for all outbound traffic.
3) Have the SPF information in your DNS records. Don't put your block of IP's in SPF record, just the one IP that you use for sending email. Make sure there is a "-all" in the records so that it makes it clear that all other email claiming to be you is discarded by other server.
4) You will need to setup Feed Back Loops and proper SWIP (If possible) contact information. You will need to go to the big 10 ISP's and submit the FBL information to them and get put on their White Lists. Don't lie to them, just tell them your personal email server that is having issues sending mail to them and you want to get on their White List. FBL's are usually for people who send high volumes of mail, include Newsletters and some "spammy" mail, but I find it helps regular mail servers if you set up FBL information.