Mail to external users and same mail domain

Hi@all,

we use UCS/Kolab as our mail system. Our mail domain is:
company.com
We have three external users whose may address is in the same domain:

user1@company.com
user2@company.com
user2@company.com

These do not access the UCS/Kopano but fetch/transmit their mails directly from/via ISP (Strato) with Thunderbird. This all works as well.

But if we want to send a mail to these people from here internally via the Kopano server, this does not work because Postfix does not know what is logical.

Under Kolab I had always edited the line “/etc/postfix/main.cf”:

transport_maps = hash:/etc/postfix/transport, hash:/etc/postfix/external_user

and then created the file “/etc/postfix/externe_user”:

user1@company.com smtp:smtp.strato.com
user2@company.com smtp:smtp.strato.com
user3@company.com smtp:smtp.strato.com

and afterwards:

postmap /etc/postfix/external_user
service postfix restart

When I try to send mail to user1@company.com from within the company I get a message in the logfile:

Aug 04 10:11:56 saturn postfix/smtpd[15623]: connect from localhost[127.0.0.1]
Aug 04 10:11:56 saturn postfix/smtpd[15623]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 550 5.1.1 <user1@company.com>: Recipient address rejected: User unknown in virtual mailbox table; from=<andreas@company.com> to=<user1@company.com> proto=ESMTP helo=<saturn.intern.lan>
Aug 04 10:11:56 saturn kopano-spooler[15616]: RCPT line gave SMTP error 550 5.1.1 <user1@company.com>: Recipient address rejected: User unknown in virtual mailbox table. (no retry)
Aug 04 10:11:56 saturn postfix/smtpd[15623]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=0/1 data=0/1 quit=1 commands=3/5
Aug 04 10:11:56 saturn kopano-spooler[15616]: SMTP: Error while executing command 'DATA'. Response: 554 5.5.1 Error: no valid recipients
Aug 04 10:11:56 saturn kopano-spooler[15616]: E-mail for user "Andreas.Stedry" could not be sent: cancel message (40580). Notifying user.

what have I forgotten?

with best
sven

Please check, whether the line

transport_maps = hash:/etc/postfix/transport, hash:/etc/postfix/external_user

still exists in main.cf. You should add “, hash:/etc/postfix/external_user” in Univention registry to prevent from deletion.

If you also speak German, please find this thread - maybe it moght help you:

To add to the above afair you still would need objects in the ldap tree for user1@company.com, …

As Postfix first tries to resolve the user from ldap before the transport maps come into play.

Okay, it’s working.

As fbartels wrote, you have to create the users in LDAP with their mail address (option Kopano-User = None).

Then for each user:

ucr set mail/maps/transport/USER1='user1@company.com smtp:[smtp.strato.de]'

with best
sven

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