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Hi all<br />
<br />
We are currently getting a lot of complaints of bounceback emails from our server. It is not for all email addresses, only some but for the ones who it occurs all the time.<br />
<br />
The message we receive is: <br />
<br />

<pre><code id="code-10-28696756-1">[213.249.141.122] #&lt;[213.249.141.122] #5.0.0 smtp; 5.3.0 - Other mail system problem 550-'5.7.1 Sorry, message looks like spam or phish to me (OP)'</code></pre>
.<br />
<br />
We have disabled both the Spam Filter and AV temporarily and it still occurs.<br />
<br />
Cheers<br />
Dom
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Hi all

We are currently getting a lot of complaints of bounceback emails from our server. It is not for all email addresses, only some but for the ones who it occurs all the time.

The message we receive is: 

(CODE).

We have disabled both the Spam Filter and AV temporarily and it still occurs.

Cheers
Dom

5.7.1 Bounce Back - MDaemon Server

Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol (SMTP). The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.

Email Servers

Various techniques are used to prevent email spam (unsolicited bulk email). No technique is a complete solution to the spam problem, and each has trade-offs between incorrectly rejecting legitimate email (false positives) vs. not rejecting all spam (false negatives) - and the associated costs in time and effort. Anti-spam techniques can be broken into four broad categories: those that require actions by individuals, those that can be automated by email administrators, those that can be automated by email senders and those employed by researchers and law enforcement officials.

AntiSpam

Interactions between email servers and clients are governed by email protocols. The three most common email protocols are POP, IMAP and MAPI. Most email software operates under one of these (and many products support more than one).  The correct protocol must be selected, and correctly configured, if you want your email account to work.