How to Configure Lazy approval in SP 2013 with Exchange 2010 ?.
LazyApproval doesn't work on a specific mail server. It works on the concept of your SharePoint environment supports email-enabled document libraries, which works around SMTP. So it should work with pretty much any mail server.
Once your SP environment can handle email enabled document libraries, LazyApproval will just work.
You just need to make sure your LazyApproval email doesn't have a mail box in your mail server.
Take a look at this :
Further to Vadim's response, I have found this guide provides some useful additional detail:
Although it mentions SharePoint 2007/Exchange 2007 - you will note the process is virtually identical.
Test by setting up a standard inbound SharePoint document library - if that works then Nintex will be happy.
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