[Exim] Exim 3.33 compatibilty with 4

Will my directors that I've written for Exim 3.33 configurarion work for Exim 4. Things like LDAP lookups. Or do these have to be rewritten in another format. Will our Exim 3.33 system filters work also in Exim 4 or do they need rewrite also?


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Joseph Kezar