Unresolvable destination host results in queued messages
Last Updated January 17, 2018
When configuring delivery for a specific domain using the Delivery->Destination Routing->Destination Hosts pane of the Protocols->Domains page, configuring a hostname that cannot be resolved in the DNS as one of the destination hosts will cause the domain to be marked as undeliverable and messages to that domain will be queued in the delivery queue.
2010 Dec 10 09:58:03 IST (debug) ecelerity:  ds_cache: static_route =(string)<test.sbmf.com:26?pref=1 test1.com:25?pref=1 [10.217.33.188]:26?pref=1>
2010 Dec 10 10:28:42 IST (info) ecelerity:  smsrouting: hard DNS error \'Timeout while contacting DNS servers\' during MX lookup of \'test1.com\'; unroutable messages may be stuck in domain container \'#sms#00000001\'
2010 Dec 10 10:28:13 IST (info) ecelerity:  ML-TRANSFAIL: Message ID: 30/00-12172-D5CA10D4, Audit ID 0ad921ba-b7cc8ae000002f8c-00-4d01ac5d7380, Temporary delivery failure, sender: email@example.com, recipient: firstname.lastname@example.org, Detail: 454 4.4.4 [internal] no MX or A for domain
This behavior is the consequence of a misconfiguration of the Destination Routing. When the domain route is being cached the failure to resolve one of the destination hosts results in the domain being marked as 'unroutable' and messages to that domain queued.
Please ensure that the hostnames used in configuring the Delivery->Destination Routing are resolvable in the DNS or substitute IP addresses if needed. Alternately, you can configure destination routing via MX or LDAP directory data source.
To confirm that the appliance can resolve destination hosts, please use the nslookup tool located on the Administration->Utilities page.
Imported Document ID: TECH166790
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