Autoreply & Vacation Messages with "<>" from address?


Verified User
Jul 10, 2019

I've been researching for the past two days trying to figure out what exactly is going on with an issue I'm having with outgoing mail on my servers. I'm a bit of a noob when it comes to reading and troubleshooting mail issues and hope someone can help me make some sense of it!

Our servers were being blocked (by Microsoft primarily) for having a bad sending reputation. Despite not having any history reported on SNDS with Microsoft, we tried to have the IPs mitigated, but they rejected our request. All this being said, we decided to purchase Outbound SMTP services from Duocircle and are sending all our mail through that service.

Duocircle requires you to add the outbound domains to their control panel along with some SPF records to each domain in order for the mail to be sent.

I've implemented the changes here: and am successfully routing mail through Duocircle's servers but I've run into an issue with Auto Reply and Vacation messages. They don't appear to be getting sent and instead are sitting frozen in my mail queue.

The original email came from, to My server is sending a vacation reply to

When I go look at the logs for the frozen messages in the Mail Queue Admin I see the following (I've anonymized some parts):


mail 8 12
1592390342 0
-received_time_usec .938064
-ident mail
-received_protocol local
-aclm _uid 2
-aclm _caller_user 4
-aclm _user 0

-aclm _username 7
-body_linecount 13
-max_received_linelength 74
-frozen 1592390344

154P Received: from mail by with local (Exim
id 1jlVTC-0001c2-UG
for; Wed, 17 Jun 2020 06:39:02 -0400
030F From:
042T To: UserFirstName UserLastName <>
038 Subject: Out Of Office: "Testing 123"
059 In-Reply-To: <>
058 References: <>
029 Auto-Submitted: auto-replied
018 MIME-Version: 1.0
040 Content-Type: text/plain; charset=UTF-8
032 Content-Transfer-Encoding: 8bit
057I Message-Id: <>
038 Date: Wed, 17 Jun 2020 06:39:02 -0400


2020-06-17 06:39:02 Received from <> R=1jlVTA-0001b8-78 U=mail P=local S=940 T="Out Of Office: \"Testing 123\""
2020-06-17 06:39:04 [] SMTP error from remote mail server after RCPT TO:<>: 554 5.7.1 Account simplificare is not allowed to relay bounces
2020-06-17 06:39:04 F=<> R=smart_route T=auth_relay [] X=TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256 CV=yes: SMTP error from remote mail server after RCPT TO:<>: 554 5.7.1 Account simplificare is not allowed to relay bounces
*** Frozen (delivery error message)

I've circled back with Duocircle and they told me it was appearing as a bounce to them because the vacation message was appearing with a null "<>" from address (see the first line in the Log portion). They suggested the could whitelist "<>" from on my account but that sounded like a bad idea.

What I don't understand is why the outbound message is appearing to come from "<>" instead of from the

I'm sure this is a simple fix that I'm just not seeing, and would greatly appreciate some help!



Staff member
Aug 22, 2006
We don't want autoreplies to get any autoreplies to them. That's a usual practise, bounce messages work this way too.


Verified User
Jul 10, 2019
Ok. I get that. The endless auto reply loop issue.

Is there any way it could be set to a non-existent user that black holes the second auto reply (if it occurs), or maybe to a system account that empties itself every so often? I need the main auto reply to identify as from a domain, so the outgoing SMTP will work.