cron job with php-ews to get only new emails from Exchange server - exchange-server

Question

I need a cron job to obtain only the new emails received in a Exchange server since the last time it synchronized.
I coded the same with imap servers, and it was easy to get the emails since an ID. So I save the last ID at the end of the for cycle to the DB, and resume from that ID the next time the cron job executes.
I tried the same in Exchange, but I get the following error:
Failed to search for messages with "ErrorInvalidValueForProperty: El valor especificado no es válido para la propiedad."
To get the ItemId in Exchange I'm using the following code, with no error:
$item->ItemId->Id;
It returns something like:
AAMkADk3ZWRhY2VmLTdiY2UtNDkxYy04ZDMyLWZiZWIyYTQ4ZjQyMABGAAAAAAChH5wDkXAqTZaoH1oRodz8BwD8BvGliMkPTK/cnnmZJDPUAAAAvGXfAAD8BvGliMkPTK/cnnmZJDPUAAAAvJN5AAA=
To find the emails I'm trying the following code (with the error mentioned before):
$request = new FindItemType();
$request->ParentFolderIds = new NonEmptyArrayOfBaseFolderIdsType();
$request->Traversal = ItemQueryTraversalType::SHALLOW;
$greater_than = new IsGreaterThanOrEqualToType();
$greater_than->FieldURI = new PathToUnindexedFieldType();
$greater_than->FieldURI->FieldURI = UnindexedFieldURIType::ITEM_ID;
$greater_than->FieldURIOrConstant = new FieldURIOrConstantType();
$greater_than->FieldURIOrConstant->Constant = new ConstantValueType();
$greater_than->FieldURIOrConstant->Constant->Value = $UID;
Thanks!!

Answer 1

The EWS ItemId isn't a searchable property because it doesn't need to be eg you can just Bind to the Id in question to see if the Item exists. If it nolonger exists then you will get a specific error to tell you that. The SyncFolderItems operation is probably a more appropriate method to use however https://learn.microsoft.com/en-us/exchange/client-developer/web-service-reference/syncfolderitems-operation.