This is to share on how to prevent the problem of ending up in these email providers Spam folders. Using CiviCRM contact mail link and Civimail, I have continually ended up in these forlders.
I will touch on Yahoo first then come back later to Gmaill and Hotmail
FIRST go here to test http://senderid.espcoalition.org/ then you will see, most likely you are missing some settings.
2. Then this site will help you find you SPF settings http://old.openspf.org/wizard.html
3. Once done try the test site again and you will see better results. Now you will also see your email go into the Yahoo Inbox.
Yahoo also has a form you can get to get you off the list http://help.yahoo.com/l/us/yahoo/mail/postmaster/forms_index.html
Let them know what you want and you will get a form like http://forum.civicrm.org/index.php/topic,1484.msg6480.html#msg6480
You will see there the form they sent me and the good advice given.
1. Following the above is a good start. This helped overall with my email to Google.
Coming soon more on this.
1. Make sure all your mail servers accept mail from: delivery notifications (NDR)