If you are having trouble with Google putting your emails into spam folders, email to yourself at Gmail. Then examine the original headers ("show original") and check the authentication header Google adds. It begins:
Authentication-Results: mx.google.com;
and details what it did and did not like about your message. For example, it let me know my mail server had suddenly started sending over IPv6 (actually, Google started accepting there and IPv6 had priority) and I only had SPF records for the IPv4 address. Google's authentication results are the friend of everyone with a personal mail server.
Authentication-Results: mx.google.com;
and details what it did and did not like about your message. For example, it let me know my mail server had suddenly started sending over IPv6 (actually, Google started accepting there and IPv6 had priority) and I only had SPF records for the IPv4 address. Google's authentication results are the friend of everyone with a personal mail server.