[OSGeo] #3009: Replace postgrey with postscreen

[OSGeo]

#3009: Replace postgrey with postscreen
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 Reporter:  strk              |       Owner:  sac@…
     Type:  task              |      Status:  new
 Priority:  normal            |   Milestone:  Sysadmin Contract 2023-II
Component:  SysAdmin/Postfix  |  Resolution:
 Keywords:                    |
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Comment (by neteler):

 Sounds good, it hopefully also stops this rubbish:

 https://lists.osgeo.org/pipermail/grass-web/2023-November/date.html

 The spammer is not subscribed, the list is moderated and still it comes
 through :(
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Ticket URL: <https://trac.osgeo.org/osgeo/ticket/3009#comment:7>
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