Fix data clobbering issue when getting Quota Exceeded status (#4144)

Don't clobber the Quota Exceeded status once we get it

Add unit test to make sure this doesn't happen

---

#### Does this PR need a docs update or release note?

- [x] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [ ] ⛔ No

#### Type of change

- [ ] 🌻 Feature
- [x] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup

#### Test Plan

- [ ] 💪 Manual
- [x] ⚡ Unit test
- [ ] 💚 E2E

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased] (beta)
 
+### Fixed
+- Exchange backups would fail attempting to use delta tokens even if the user was over quota
+
 ## [v0.12.0] (beta) - 2023-08-28
 
 ### Added

src/pkg/services/m365/api/users.go

@@ -238,7 +238,7 @@ func (c Users) GetInfo(ctx context.Context, userID string) (*UserInfo, error) {
 			return nil, clues.Stack(err)
 		}
 
-		userInfo.Mailbox.QuotaExceeded = graph.IsErrQuotaExceeded(err)
+		mi.QuotaExceeded = graph.IsErrQuotaExceeded(err)
 	}
 
 	userInfo.Mailbox = mi

src/pkg/services/m365/api/users_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/h2non/gock"
 	"github.com/microsoftgraph/msgraph-sdk-go/models"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 
 	"github.com/alcionai/corso/src/internal/m365/graph"
@@ -250,3 +251,29 @@ func (suite *UsersIntgSuite) TestUsers_GetInfo_errors() {
 		})
 	}
 }
+
+func (suite *UsersIntgSuite) TestUsers_GetInfo_quotaExceeded() {
+	t := suite.T()
+	ctx, flush := tester.NewContext(t)
+
+	defer flush()
+	defer gock.Off()
+
+	gock.EnableNetworking()
+	gock.New(graphAPIHostURL).
+		// Wildcard match on the inbox folder ID.
+		Get(v1APIURLPath("users", suite.its.userID, "mailFolders", "(.*)", "messages", "delta")).
+		Reply(403).
+		SetHeaders(
+			map[string]string{
+				"Content-Type": "application/json; odata.metadata=minimal; " +
+					"odata.streaming=true; IEEE754Compatible=false; charset=utf-8",
+			},
+		).
+		BodyString(`{"error":{"code":"ErrorQuotaExceeded","message":"The process failed to get the correct properties."}}`)
+
+	output, err := suite.its.gockAC.Users().GetInfo(ctx, suite.its.userID)
+	require.NoError(t, err, clues.ToCore(err))
+
+	assert.True(t, output.Mailbox.QuotaExceeded)
+}