Hi, I hope yall can help.
We have an exchange 2003 environment (Native Mode). I have a few users accross the company that get NDR #5.7.1 which basically says"You do not have permissions to send to this recipient..."
This does not happen all the time, just occasionally. They are able to send to the same address ok, but then some times they get the NDR. I check the event logs and we are getting alot of EVent 7004 errors. Which says "This is an SMTP protocol error log for virtual Server ID 1, connection #310. The remote host "xxx.xxx.xxx.xxx", responded to the SMTP command sent "xexch50" with "504 Need to authenticate first". The full commad sent was "XEXCH50 2144 2". This wil probably cause the connection to fail.
I do not know if these two issues are related. I do not think so, because we are getting this event every few minutes or so, and the NDR's are not near that often, maybe one every few days. I have looked at various articles and have had no luck. Has anyone seen this before? Any Ideas?
This is difficult because it is random, at least the NDR #5.7.1. is. An interesting note, when looking at articles for the event ID 7004, The remote host has a FQDN. I get only IP's. Not sure if that has any meaning. I did read some where that its possible DNS issue. Please help!