Thought I was having the same issue, but the only address it fails on is the Apple ID signed in to icloud - just happened to be the external address I was testing outgoing mail with initially. Seems an odd coincidence but every other external address I've tried has been successful.
Need to move on to testing incoming external mail - tomorrow I think, once my head's cleared!
Would be interested to know if this has any similarity to your issue.
Quick update on this...
After digging through the logs it seems the missing messages were being re-routed to the admin account on the server, and sure enough examining the user details showed an alias of the Apple ID as an entry there. Removing that enabled emails to be sent to the external address. The Apple ID presumably was populated there during intial setup.
Hope this is useful if anybody else hits the same oddity.
Okay so I tried following the Mail through the mail.log file but I don't really understand what is happening. Maybe one of you could be so kind and tell whats going on.
This is what is happening in my log file if I send an E-Mail from an server account to a @live.de account:
Dec 5 14:32:14 redra1n.net postfix/smtpd: connect from p5dc150c9.dip.t-dialin.net[220.127.116.11]
Dec 5 14:32:14 redra1n.net postfix/smtpd: E4D6F5E75C: client=p5dc150c9.dip.t-dialin.net[18.104.22.168], sasl_method=PLAIN, sasl_username=CJ
Dec 5 14:32:15 redra1n.net postfix/cleanup: E4D6F5E75C: message-id=<Edited By Host>
Dec 5 14:32:15 redra1n.net postfix/qmgr: E4D6F5E75C: from=<Edited By Host>, size=544, nrcpt=1 (queue active)
Dec 5 14:32:15 redra1n.net postfix/smtpd: connect from localhost[127.0.0.1]
Dec 5 14:32:15 redra1n.net postfix/smtpd: 5F8885E76A: client=localhost[127.0.0.1]
Dec 5 14:32:15 redra1n.net postfix/cleanup: 5F8885E76A: message-id=<Edited By Host>
Dec 5 14:32:15 redra1n.net postfix/smtpd: disconnect from localhost[127.0.0.1]
Dec 5 14:32:15 redra1n.net postfix/qmgr: 5F8885E76A: from=<Edited By Host>, size=955, nrcpt=1 (queue active)
Dec 5 14:32:15 redra1n.net postfix/smtp: E4D6F5E75C: to=<Edited By host>, relay=127.0.0.1[127.0.0.1]:10024, delay=0.47, delays=0.12/0.01/0/0.34, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as 5F8885E76A)
Dec 5 14:32:15 redra1n.net postfix/qmgr: E4D6F5E75C: removed
Dec 5 14:32:16 redra1n.net postfix/smtp: 5F8885E76A: to=<Edited By Host>, relay=mx3.hotmail.com[22.214.171.124]:25, delay=1.4, delays=0/0.01/0.57/0.82, dsn=2.0.0, status=sent (250 <Edited By Host> Queued mail for delivery)
Dec 5 14:32:16 redra1n.net postfix/qmgr: 5F8885E76A: removed
Dec 5 14:33:15 redra1n.net postfix/smtpd: disconnect from p5dc150c9.dip.t-dialin.net[126.96.36.199]
//The E-Mail gets delivered within seconods..
But if I reply on the E-Mail nothing happends in my inbox and it's pretty much the same with the log file. The EMail just doesn't arrive at my server then I guess......
<Email Edited by Host>
I get a Postmaster EMail after hours telling me that my EMail is delayed because of:
Will-Retry-Until: Thu, 6 Dec 2012 15:46:39 -0800
I've set up two MX-Records: mx1.redra1n.net(priority=10) and mx2.redra1n.net(priority=20) and I've put them into the backend of my domain provider. I also entered my static IP as an A-Record. My Wiki, Website, Profilemanager are all running perfectly fine. I have just no idea what the whole problem is...
I take it you don't have much experience with DNS. It's pretty essential if you want to have a outward facing server. If you can, I'd suggest purchasing this book... http://shop.oreilly.com/product/9780596100575.do
First and foremost, you need a computer record (A record) that has a hostname. In the image above, you seem to have created a machine record that just has the domain ("redra1n.net"). You need to change that to represent a machine *within* the domain ("somemachine.redra1n.net"). Then, create an MX record that points to the same machine record ("somemachine.redra1n.net").
Okay so I made this now...
The machines (mx01/mx02) are looking like that:
And the MX-Records (mx01/mx02) are looking like that:
In general it looks like that now and if I uncheck the show all records and the look into mx01/02 the checkmark for create and MX-Records is checked automatically. I guess it worked then.