Our company has been using the 3rd party service Asana.com for the past year. Last week their system alerts stopped being delivered and Asana was receiving error 550 5.7.1 Access denied from our Exchange 2010 system. To me this usually meant a configuration issue within their DNS record that our system didn't like.
Then everything became sporadic. We would get some of the alerts, some users received more and some users received zero.
I have been in contact with Asana support. The only thing I could find was running a DNS report on Asana.com I would get the following error: Malformed greeting or no A records found matching banner text for following servers, and banner is not an address literal.
Asana.com does have a SPF record. They use google apps for email and a couple of 3rd party mail list programs.
We have went thru a few troubleshooting steps and I have added Asana.com to our Exchange 2010 white list. Anything else that I can try or have them modify on their end I would appreciate it.
I had to explain to them why I would not modify my system to be an open relay.
We do not have any issues receiving alerts from any other system and Asana reps say the same thing. Unfortunately all troubleshooting will have to start from my end, they won't assist proactively without my prompting. I am just running out of ideas of what I can do on my side.