Mailbox Management with Microsoft Graph

In addition to working with messages, folders, and attachments, Aspose.Email for Java also allows you to manage mailbox-level features such as categories, focused inbox overrides, and rules. You can also work with multiple mailboxes by switching the resource context. These operations are available through the Graph API integration.

How to Work with Outlook Categories

Categories in Outlook allow you to group and label messages for easier organization. With Aspose.Email, you can create, fetch, update, list, and delete categories programmatically.

String categoryName = "Test Category";
int preset = CategoryPreset.Preset10;

// create a new category
OutlookCategory category = client.createCategory(categoryName, preset);

// fetch a category
OutlookCategory fetchedCategory = client.fetchCategory(category.getId());

// list categories
List<OutlookCategory> categories = client.listCategories();

// update a category
fetchedCategory.setDisplayName("Update Category");
fetchedCategory.setPreset(CategoryPreset.Preset11);
OutlookCategory updatedCategory = client.updateCategory(fetchedCategory);

// delete a category
client.delete(category.getId());

How to Work with Overrides

Overrides control how messages from certain senders are treated in the Focused Inbox. For example, you can force messages from a specific sender to always appear in the focused view.

int focusedType = ClassificationType.Focused;

// create or update an override for a sender
ClassificationOverride override = client.createOrUpdateOverride(
    new MailAddress("testUser@host.com", "testUser"), focusedType
);

// list overrides
List<ClassificationOverride> list = client.listOverrides();
for (ClassificationOverride item : list)
    System.out.println(item.getSender().getAddress());

// update override classification
ClassificationOverride fetchedOverride = list.get(0);
fetchedOverride.setClassifyAs(ClassificationType.Other);
fetchedOverride.getSender().setDisplayName("testUser_1");
ClassificationOverride updatedOverride = client.createOrUpdateOverride(fetchedOverride);

// reset classification
fetchedOverride.setClassifyAs(ClassificationType.Focused);
updatedOverride = client.updateOverride(fetchedOverride);

// delete override
client.delete(updatedOverride.getId());

How to Work with Outlook Rules

Mailbox rules allow you to automate actions such as forwarding messages or filtering based on conditions. The Graph API allows creating, fetching, updating, listing, and deleting inbox rules.

// create a new rule
InboxRule rule = new InboxRule();
rule.setDisplayName("Test rule");
rule.setPriority(1);
rule.setEnabled(true);
rule.setConditions(new RulePredicates());
rule.getConditions().containsSenderStrings(new StringCollection());
rule.getConditions().containsSenderStrings().addItem("testUser");

// define actions
rule.setActions(new RuleActions());
rule.getActions().setForwardToRecipients(new MailAddressCollection());
rule.getActions().getForwardToRecipients()
    .addMailAddress(new MailAddress("testUser@host.com", "testUser", true));
rule.getActions().setStopProcessingRules(true);

InboxRule createdRule = client.createRule(rule);

// list rules
List<InboxRule> listedRules = client.listRules();
for (InboxRule item : listedRules)
    System.out.println(item.getDisplayName());

// fetch and update a rule
InboxRule fetchedRule = client.fetchRule(createdRule.getRuleId());
createdRule.setDisplayName("Test rule 1");
createdRule.setEnabled(false);
InboxRule updatedRule = client.updateRule(createdRule);

// delete rule
client.delete(createdRule.getRuleId());

Working with Multiple Mailboxes - Switching Mailbox Context

By default, operations are performed against the current user’s mailbox. You can switch the context to another mailbox (for example, to list messages from a shared mailbox) by setting the resource type and resource ID.

// switch to another mailbox
client.setResource(ResourceType.Users);
client.setResourceId("mailbox");
client.listMessages("mailfolder");

// switch back to the current user mailbox
client.setResource(ResourceType.Me);

OData Queries with Microsoft Graph

Aspose.Email for Java provides support for OData queries when working with Microsoft Graph. It allows you to perform advanced filtering, ordering, selection, paging, and expansion when retrieving resources such as folders, messages, contacts, and calendar items. The ODataQueryBuilder class allows you to construct OData query parameters in a structured and reusable way instead of manually building query strings. The following methods can be applied for counting and searching across large datasets:

  • Select to retrieve only the properties you need.
  • Filter to apply filters.
  • OrderBy to sort results.
  • Top and Skip for pagination.
  • Expand to expand related entities in a single query.

Several GraphClient methods accept an optional ODataQueryBuilder parameter for applying OData queries, including:

  • listFolders
  • listMessages
  • listContacts
  • listCalendarItems
  • listAttachments
  • listCategories
  • listOverrides
  • listRules
  • listTaskLists
  • listTasks
  • listNotebooks

The following code sample shows how to use ODataQueryBuilder to query folders and retrieve messages with advanced filters and paging:

IGraphClient client = GraphClient.GetClient();

client.setResource(ResourceType.Users);
client.setResourceId(username);
client.setEndpoint("https://graph.microsoft.com");

// Example 1: List folders ordered by name
ODataQueryBuilder builder = new ODataQueryBuilder();
builder.setOrderBy("name asc");

GraphFolderInfoCollection folders = client.listFolders(builder);
for (GraphFolderInfo folder : folders) {
    System.out.println(folder.getDisplayName());
}

String folderId = folders.get(0).getItemId();

// Example 2: Retrieve filtered and paged messages
builder = new ODataQueryBuilder();
{
    builder.setFilter("startswith(name,'A')");
    builder.setOrderBy("name asc");
    builder.setTop(10);
    builder.setSkip(5);
    builder.setSelect(new String[]{"name", "age"});
    builder.setExpand(new String[]{"children", "parents"});
    builder.setCount(true);
    builder.setSearch("\"John Doe\"");
    builder.setFormat("json");
};

GraphMessageInfoCollection msgs = client.listMessages(folderId, builder);
for (GraphMessageInfo msg : msgs) {
    System.out.println(msg.getSubject());
}
Working with Microsoft Graph in Aspose.Email for Java