OK I think I've found a few things.   
	Code:
	Return-path: <team.seti.usa@gmail.com>
Return-path: <team.seti.usa@gmail.com>
Return-path: freedc.bok@gmail.com
 is team.seti.usa@gmail.com the actual account that is being used and authenticated against when an e-mail is sent out of vbulletin?    This could trigger a spam filter.   I see a different e-mail address used as the source below.  (in red)
	Code:
	
From: "SETI.USA Forums" <team.seti.usa@gmail.com>
Subject: New Private Message at SETI.USA Forums
[B]X-Originating-IP: [209.85.160.181]
 
I don't see a SPF record existing for the domain.    This would tell relayers that Google's servers are authorized to send e-mail from www.setiusa.us.   openspf.org has good instructions on how to do this.   I can help with this
	Code:
	To: jthet@verizon.net
Message-id: <20150416110903.7d9890b7f777@www.setiusa.us>
Auto-submitted: auto-generated
MIME-version: 1.0
X-Mailer: vBulletin Mail via PHP
Content-type: text/plain; CHARSET=US-ASCII
Content-transfer-encoding: 7BIT
X-Priority: 3
X-Verizon-Spam: Yes
X-CMAE-Score: 100
X-CMAE-Analysis: v=2.1 cv=Edh/m0jq c=1 sm=1 tr=0	p=loIXWkM1L7FDsMoH8zRTmg==:17
 a=KF4uY4r1RTM9ztufGXkfiw==:117	a=8nJEP1OIZ-IA:10 a=pGLkceISAAAA:8
 a=JMeYN1-FAAAA:8 a=1XWaLZrsAAAA:8	a=oR5dmqMzAAAA:8 a=ayC55rCoAAAA:8
 a=-9mUelKeXuEA:10 a=1oJP67jkp3AA:10	a=ZZnuYtJkoWoA:10 a=e9J7MTPGsLIA:10
 a=XJfPAMEUAAAA:8	a=uvqjVyVQfQ0fRN2MxhsA:9 a=wPNLvfGTeEIA:10 a=14El-3rh7mgA:10
	a=rZDDTEz154YA:10 a=OiDYEkROhFoA:10 a=NWVoK91CQyQA:10
X-Google-Original-From: "SETI.USA Forums" <freedc.bok@gmail.com>
 Is the freedc.bok@gmail.com address what's being used to authenticate to Gmail?   This could cause problems as well.  
I can definitely help with a few nuts & bolts on this.   It will require access to whomever hosts the dns records (most likely easydns from what my dig commands are telling me).     We are on a few blacklists as well.   http://mail-blacklist-checker.online-domain-tools.com.