Faster mail load from Exchange

You may want to look into querying your mail messages via Graph API.

Some caveats:

1. I have not used this directly in a while, so just going off memory / quick research / testing with Graph Explorer sample tenant.
2. Graph integration with PBI is quite limited. Last I checked, though, you could still connect to personal mail through simple http calls and using PBI oauth. See MS party line on this: https://learn.microsoft.com/en-us/power-query/connecting-to-graph
3. For a more enterprise solution, you may want to look into the MS recommended route of Graph Data Connect through Data Factory

Connecting would look something like this:

Web.Contents(
    "https://graph.microsoft.com/v1.0",
    [
        // can query me/mailFolders and nav via childFolders; eg me/mailFolders/<id>/childFolders/<id>/messages
        RelativePath = "me/mailFolders/inbox/messages", 
        Headers = [ accept = "application/json" ],
        Query = [
            #"$orderby" = "sentDateTime desc",
            // props list for select: https://learn.microsoft.com/en-us/graph/api/resources/message#properties
            #"$select" = "id,sentDateTime,from,subject,bodyPreview", 
            // eg filter to this year; datetime format is ISO 8601 (eg 2025-01-01T00:00:00Z)
            #"$filter" = "sentDateTime ge 2025-01-01", 
            #"$top" = "100" // I believe max is 1000 - adjust as needed for performance
        ]
    ]
)

Parse the response as JSON (Json.Document). You'll get a JSON record with fields:

• value: list of records to upack with Table.FromRecords
• @odataNextLink: if more records exist than specified in $top, this will give the REST url for next page of size $top