Incoming mail blocked by Exchange 2010 antispam, how to unblock?

This is using MS Exchange 2010 server with antispam. There is a mail blocked by antispam with  the following messages:

  The following message to <> was undeliverable.
The reason for the problem:
5.3.0 - Other mail system problem 550-'5.7.1 Message rejected as spam by Content Filtering.'

Suppose the sender email domain is, how to unblock it in antispam?

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MezzutOzilAuthor Commented:
Hi Papertrip,

For adding whitelisting email addresses..

  $list = (Get-ContentFilterConfig).BypassedSenders
Set-ContentFilterConfig -BypassedSenders $list

Does this mean that everytime I wanted to add in new email address, I have to rerun the above 3 commands? with the only change on "$list.add(")?

As far as I know there is no way to dynamically add addresses into BypassedSenders, however I'm not an Exchange pro.
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MezzutOzilAuthor Commented:
That means MANUAL way is possible, right?
From what I have read, yes you must do it manually as per the link I posted.

If any experts know a way for the list to somehow be populated automatically, please explain.
MezzutOzilAuthor Commented:
It works great
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