A couple of days ago a friend drew my attention to the fact that messages from my domain host had started generating spam warnings when I emailed his gmail account. On checking (by emailing my own gmail account from my domain account) I had the same experience. The message, for anyone who hasn't yet seen it, reads:
Be careful with this message.
Gmail could not verify that it actually came from
mydomainname.com. Avoid Clicking links,
downloading attachments or replying with
personal information.
The warning includes Report spam and Report phishing buttons. If you follow the Information links, it says that the message seems fraudulent or dangerous, and to click (absent from all dialogues)
Looks safe or
Ignore if you're confident it isn't
I'm not sure when gmail started doing this, but on looking at it more closely it appears to happen with all emails sent from any SMTP server on which SPF/DKIM hasn't been enabled.
On my main domain (where DNS and SMTP share the same host), enabling SPF instantly removed the warning on subsequent messages to gmail. However, on domains where DNS and SMPT are on different servers, I have yet to discover a solution (and tech advisors on SMTP and domain servers have hitherto failed to suggest anything that seems to work).
Does anyone know anything about this issue? It is obviously a big problem for anyone answering client queries where the client uses a gmail account.