Hide local IP from non delivery notifications
Hi everyone,
I have an external MTA configured with Postfix that delivers email to an internal IMAP/LMTP Dovecot server configured to bind an LDAP to check if users exist.
If the user does not exist, my MX sends a non delivery notification, and into the e-mail there's the local IP address of the Dovecot server.
I can't find a way to remove or hide that IP, here is an example of line that contains the IP (with X) that I would like to hide/remove:
*"The mail system<user@domain>: host hostname.domain.com <http://hostname.domain.com>[XXX.XXX.XXX.XXX] said: 550"*
Thanks in advance!
Cheers
-- Claudio
"Claudio" == Claudio Corvino <c.corvino81@gmail.com> writes:
I have an external MTA configured with Postfix that delivers email to an internal IMAP/LMTP Dovecot server configured to bind an LDAP to check if users exist.
You should have postfix do the checking for whether or not users exist and then have postfix reject and deny the message. Then you don't care because the IP of the postfix server is almost certainly your MX server.
If the user does not exist, my MX sends a non delivery notification, and into the e-mail there's the local IP address of the Dovecot server.
I can't find a way to remove or hide that IP, here is an example of line that contains the IP (with X) that I would like to hide/remove:
"The mail system
<user@domain>: host hostname.domain.com[XXX.XXX.XXX.XXX] said: 550"
Thanks in advance!
Cheers
-- Claudio
I have an external MTA configured with Postfix that delivers email to an internal IMAP/LMTP Dovecot server configured to bind an LDAP to check if users exist.
You should have postfix do the checking for whether or not users exist and then have postfix reject and deny the message. Then you don't care because the IP of the postfix server is almost certainly your MX server.
Plus backscatter. Sending a fail notification back to the sender (vs rejecting) puts your mail server at risk of sending spam to email accounts that had their address forged. And thus maybe yoru server being added to a spam blacklist.
Ok thanks for your answer but I have another question: if I reject the e-mail instead of sending the non delivery notification, how can a "good" user be notified of the fact that his e-mail was not delivered?
Claudio
On 14/02/23 19:48, dovecot@ptld.com wrote:
I have an external MTA configured with Postfix that delivers email to an internal IMAP/LMTP Dovecot server configured to bind an LDAP to check if users exist.
You should have postfix do the checking for whether or not users exist and then have postfix reject and deny the message. Then you don't care because the IP of the postfix server is almost certainly your MX server.
Plus backscatter. Sending a fail notification back to the sender (vs rejecting) puts your mail server at risk of sending spam to email accounts that had their address forged. And thus maybe yoru server being added to a spam blacklist.
On 2023-02-15 6:41 a.m., Claudio Corvino wrote:
Ok thanks for your answer but I have another question: if I reject the e-mail instead of sending the non delivery notification, how can a "good" user be notified of the fact that his e-mail was not delivered?
Claudio
That should be the job of the sender's MTA, not you.
Right! I did the setup and it works correctly!
Thanks to all
On 15/02/23 14:34, Daryl Richards wrote:
On 2023-02-15 6:41 a.m., Claudio Corvino wrote:
Ok thanks for your answer but I have another question: if I reject the e-mail instead of sending the non delivery notification, how can a "good" user be notified of the fact that his e-mail was not delivered?
Claudio
That should be the job of the sender's MTA, not you.
You're right, I think is the only way, or at least one of the simple method to accomplish this. I'll try, thanks!
Regards
Claudio
Il mar 14 feb 2023, 19:35 John Stoffel <john@stoffel.org> ha scritto:
"Claudio" == Claudio Corvino <c.corvino81@gmail.com> writes:
I have an external MTA configured with Postfix that delivers email to an internal IMAP/LMTP Dovecot server configured to bind an LDAP to check if users exist.
You should have postfix do the checking for whether or not users exist and then have postfix reject and deny the message. Then you don't care because the IP of the postfix server is almost certainly your MX server.
If the user does not exist, my MX sends a non delivery notification, and into the e-mail there's the local IP address of the Dovecot server.
I can't find a way to remove or hide that IP, here is an example of line that contains the IP (with X) that I would like to hide/remove:
"The mail system
<user@domain>: host hostname.domain.com[XXX.XXX.XXX.XXX] said: 550"
Thanks in advance!
Cheers
-- Claudio
participants (5)
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Claudio Corvino
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Claudio Corvino
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Daryl Richards
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dovecot＠ptld.com
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John Stoffel