Can't send emails [edit: not related to Migration Tool]

Yes, I have tried to send to both Gmail and Live addresses, same results. Now it works to receive emails from outside.

In order to avoid email harvester bots, I have altered the email addresses in the below log output :

<snip>

Jun 15 13:41:29 [my-host] postfix/smtpd[3968]: connect from localhost[127.0.0.1]
Jun 15 13:41:29 [my-host] postfix/smtpd[3968]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 550 5.1.1 <[me@myexternaldomain]>: Recipient address rejected: [mylocaldomain]; from=<[me@mylocaldomain]> to=<[me@myexternaldomain]> proto=ESMTP helo=<[my-host].startdedicated.net>
Jun 15 13:41:29 [my-host] postfix/smtpd[3968]: disconnect from localhost[127.0.0.1]
Jun 15 13:41:38 [my-host] dovecot: imap-login: Login: user=<[me@mylocaldomain]>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=4241, secured, session=<qPbjR1E1nAB/AAAB>
Jun 15 13:41:38 [my-host] dovecot: imap([me@mylocaldomain]): Disconnected: Logged out in=173 out=3038

</snip>

 

Pls see attached file.

 

It's ISPconfig 3 V3.0.5.4p9

 

Phew! I have spent some time in exploring this issue even more and today I decided to start all over, so I reinstalled my new server (which is the one I am having these issues with) using the guide for the Jessie Perfect Server & ISPconfig3 installation. This server is running a LAMP setup.
It simply doesn't work to send emails from this host. I tried to update the DNS so that the MX record pointed to the old server (LAMP, Debian Wheezy, ISPconfig3) and it worked perfectly both to send and receive emails (still the same domain as for the new server and I sent to the same email addresses as for the new server). Then I updated the DNS again to point the MX record pointed to the new server and nothing worked again.

What is really strange with this error is that a lot of people seem to have it and for many years back. At some point I thought it was something that had turned up with Jessie, but since errors like this goes way back (2008 is the earliest I have found so far), this "can't" be it. Many seem to have been in a hopeless situation without a solution and just bumping their threads all the time, while some other guy just replied to his own thread saying that he didn't know why, but suddenly it started working again. It seem to lack a FAQ section/guide for this type of error.

I hope that the rest of you who run into this problem find a solution and shares it with the world.

I am definitely stuck and my only option seem to be to cancel the contract for the new server. No need to rent it when I can't use it.

 

Thank you! I have cancelled the server contract already. I got p*ssed by the hosting company for their anti-customer approach (and yet I was willing to pay for their help, which was very clear). They seemed to have an idea on what the problem was.

Now I am looking for a new hosting company for dedicated servers.

I am very grateful for all the assistance I have got here!