Currently Being ModeratedJul 10, 2013 11:09 AM (in response to Reading1995)
1-Is open relay allowed by default on OS X Lion mail server?
2-Is it expected to see different results from internet open relay test tools available on the Internet that the relay is accepted?
I wouldn't expect that. However, the fact that the first example clearly reports a 'relay access denied' message makes me wonder why the first test fails...
3-Is there any further configuration/testing that can be done to make 100% sure that the Mail server is definitely not an open relay?
I'd raise the issue with Mailradar since their test appears to be failing. There are also other relay checkers you can try. Alternatively, post your server details and have other people in the community check.
Currently Being ModeratedJul 15, 2013 3:18 AM (in response to Camelot)
Thank you very much for the quick reply and for the information provided. Most appreciated! Apologies for the delay to respond. I have emailed Mailradar the results of the open relay test but I am still waiting on their response. I have tried another open relay test tool, myDNSTools.info, but it returned the same results as the Mailradar. It looks to me as if it could be a timing issue, for example the Mailradar shows that the response for the MAIL FROM: command (250 2.1.0 Ok) arrived after the RCPT TO: commnad was sent. Therefore the open relay test assumes that relay is allowed even though the the mail server response is:
554 5.7.1 <email@example.com>: Relay access denied
If this is the case, I am not sure if the timing issues is something that I can control here at my end. I was wondering if this could be caused by the spam filtering rules available in OS X Lion mail server?