Using GMail or another ISP To Prevent emails from going to Spam

Question

I was wondering would using Google's business email or another well known ISP decrease the amount of emails from going to spam folder? What are other ways of prevent emails sent from a server from be considered spam?

I currently send emails using the PHP send_mail() function.

Answer 1

Yes, using Google Apps (even the free version) for email results in very few of your outgoing mails being marked as spam.

Note two downsides that I've come across (these are present in all paid editions too):

1) If you don't have access to the server's DNS zones (as is often the case on a shared server), you wont be able to add an SPF record for your server's IP, which will increase the amount of your emails being marked as spam.

2) Google Apps deals with multiple domains quite badly, in my opinion. If you have domainA.com as your main Google Apps accounts, with domainB.com as an additional domain, then if you send mail from person@domainB.com, the headers will show From:person@domainB.com but Return-Path:person@domainA.com . In some clients, such as Outlook, this shows as From person@domainB.com on behalf of person@domainA.com and a large proportion of mail servers will mark it as spam.