Mail API deliverability issues

[Moishe]

Hi All,

Some apps have experienced delivery problems with mail recently. This
was manifested as mail being sent from the app, and quota charged, but
the mail not arriving at the destination (not even in the spam
folder).

As you can imagine, any large service that lets applications send bulk
email is something of a honeypot for spammers. We’re working
constantly to balance delivering good mail from good apps against
preventing spam. In response to an influx of spammy apps, we changed
our outbound spam filtering to be more restrictive which,
unfortunately, raised our false positive rate.

We’ve modified this change and made some others so existing apps
should be back to previous levels of email deliverability.

DKIM support is in 1.6.3, which will improve spam evaluation
considerably, and there are some good hints here about preventing your
legitimate messages from being marked as spam:
http://support.google.com/mail/bin/answer.py?hl=en&answer=81126.

We’re planning on adding some sort of feedback mechanism so your app
will know when its mail is being rejected, rather than just silently
failing. There is no definite release date planned for this.

If you are still having problems with mail deliverability, or you have
other questions, please contact us at http://goo.gl/ldsGA

Thanks-

-Moishe Lettvin
Mail API Tech Lead