Another strange problem with our UTM.
The UTM is set to only accept relayed mail from our exchange transport servers. Our transport servers send connectors point to the UTM. Works well.
We have a distribution group with 10 internal users & 10 external users. If an internal user sends to the group, all email is delivered (both internally & externally)
eg joe.bloggs@ourdomain.com > distributiongroup@ourdomain.com > sends mail to everybody @ourdomain.com & @externaldomain_A.com & @externaldomain_B.com
If an external email address emails the group, the internal emails are delivered. The external emails are delivered to the UTM and some are bounced.
eg dave.bloggs@externaldomain_A.com > distributionlist@ourdomain.com > sends to everybody at @ourdomain.com & everybody@externaldomain_B.com but bounces to everybody@externaldomain_A.com
NOTE: the different external domains here A&B. Mail goes to B but is bounced to A
So exchange is handling it and forwarding it on as it should. All I get is "bounced" in the mail manager log and in the SMTP log it says:
2016:04:28-16:33:33 gw01-1 exim-out[6865]: 2016-04-28 16:33:33 1avnwb-0001mJ-2F ** paul.bloggs@externaldomain_A.uk P=<outsidesender@externaldomain_A.uk> R=dnslookup T=remote_smtp: SMTP error from remote mail server after RCPT TO:<paul.bloggs@externaldomain_A.uk>: host mail.externaldomain_A.uk [123.123.36.163]: 550 Your mail account has been blacklisted from sending e-mails. KB17293
To me, the above is telling me that the external mail server bounced this email back by saying that the outsidesender@externaldomain_A.uk is blacklisted?
or is the UTM saying that the outsidesender@externaldomain_A.uk is blacklisted?
The user certainly isn't blacklisted at his own domain nor is the UTM blacklisted as we can send mail to that user from within our domain.
So not sure what's going on here?
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