We have a custom built application (C#) that sends an email out to users on a distribution list (help@mydomain.com ) when there is a problem with the application.
6 users are on this DL. Only 1 user does not get the messages when the email is sent. At first I thought he had blacklisted the email address on his client, but he doesn’t.
Here is the hairy part.
We use Office365 (online) as our main mail host. Now, we have an internal STMP server running Exchange that we hook into to send the email out to help@mydomain.com
Now, that DL exists both in the Exchange Server and the Office365 environment. The user is in both DL’s on both environments.
If I log into Office365 and send an email to that DL, the user will get that email.
I wrote a simple C# app that uses the same mailer code (settings, IP address, etc), when I run the test app, the other 5 users get the message. But the 1 user doesn’t.
I am trying to narrow down why 1 user wouldn’t get the email.
