Create sub folder, delete folder, storage settings, some ui adjustments on threads.

Wino.Services/MailService.cs

@@ -1183,4 +1183,17 @@ public class MailService : BaseDatabaseService, IMailService
 
         return await Connection.QueryScalarsAsync<string>(sql, mailCopyIds.Cast<object>().ToArray());
     }
+
+    public Task<List<MailCopy>> GetMailCopiesBeforeDateAsync(Guid accountId, DateTime cutoffDateUtc)
+    {
+        const string query = """
+                             SELECT MailCopy.*
+                             FROM MailCopy
+                             INNER JOIN MailItemFolder ON MailCopy.FolderId = MailItemFolder.Id
+                             WHERE MailItemFolder.MailAccountId = ?
+                               AND MailCopy.CreationDate < ?
+                             """;
+
+        return Connection.QueryAsync<MailCopy>(query, accountId, cutoffDateUtc);
+    }
 }

Wino.Services/MimeStorageService.cs

@@ -0,0 +1,111 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Serilog;
+using Wino.Core.Domain.Interfaces;
+
+namespace Wino.Services;
+
+public class MimeStorageService : IMimeStorageService
+{
+    private readonly INativeAppService _nativeAppService;
+    private readonly IMailService _mailService;
+    private readonly ILogger _logger = Log.ForContext<MimeStorageService>();
+
+    public MimeStorageService(INativeAppService nativeAppService, IMailService mailService)
+    {
+        _nativeAppService = nativeAppService;
+        _mailService = mailService;
+    }
+
+    public Task<string> GetMimeRootPathAsync() => _nativeAppService.GetMimeMessageStoragePath();
+
+    public async Task<Dictionary<Guid, long>> GetAccountsMimeStorageSizesAsync(IEnumerable<Guid> accountIds)
+    {
+        var mimeRoot = await GetMimeRootPathAsync().ConfigureAwait(false);
+        var result = new Dictionary<Guid, long>();
+
+        foreach (var accountId in accountIds)
+        {
+            var accountPath = Path.Combine(mimeRoot, accountId.ToString());
+            result[accountId] = GetDirectorySizeSafe(accountPath);
+        }
+
+        return result;
+    }
+
+    public async Task DeleteAccountMimeStorageAsync(Guid accountId)
+    {
+        var mimeRoot = await GetMimeRootPathAsync().ConfigureAwait(false);
+        var accountPath = Path.Combine(mimeRoot, accountId.ToString());
+
+        if (Directory.Exists(accountPath))
+        {
+            Directory.Delete(accountPath, true);
+        }
+    }
+
+    public async Task<int> DeleteAccountMimeStorageOlderThanAsync(Guid accountId, DateTime cutoffDateUtc)
+    {
+        var mailCopies = await _mailService.GetMailCopiesBeforeDateAsync(accountId, cutoffDateUtc).ConfigureAwait(false);
+
+        if (mailCopies.Count == 0)
+            return 0;
+
+        var mimeRoot = await GetMimeRootPathAsync().ConfigureAwait(false);
+        var accountPath = Path.Combine(mimeRoot, accountId.ToString());
+        var fileIds = mailCopies.Select(a => a.FileId).Distinct().ToList();
+        int deletedFolderCount = 0;
+
+        foreach (var fileId in fileIds)
+        {
+            var mimeDirectory = Path.Combine(accountPath, fileId.ToString());
+
+            if (!Directory.Exists(mimeDirectory))
+                continue;
+
+            try
+            {
+                Directory.Delete(mimeDirectory, true);
+                deletedFolderCount++;
+            }
+            catch (Exception ex)
+            {
+                _logger.Warning(ex, "Failed to delete MIME directory {DirectoryPath}", mimeDirectory);
+            }
+        }
+
+        return deletedFolderCount;
+    }
+
+    private static long GetDirectorySizeSafe(string directoryPath)
+    {
+        if (!Directory.Exists(directoryPath))
+            return 0;
+
+        long total = 0;
+
+        try
+        {
+            foreach (var filePath in Directory.EnumerateFiles(directoryPath, "*", SearchOption.AllDirectories))
+            {
+                try
+                {
+                    total += new FileInfo(filePath).Length;
+                }
+                catch
+                {
+                    // Ignore unreadable files and continue calculating.
+                }
+            }
+        }
+        catch
+        {
+            return 0;
+        }
+
+        return total;
+    }
+}

Wino.Services/ServicesContainerSetup.cs

@@ -14,6 +14,7 @@ public static class ServicesContainerSetup
         services.AddSingleton<IWinoLogger, WinoLogger>();
         services.AddSingleton<ILaunchProtocolService, LaunchProtocolService>();
         services.AddSingleton<IMimeFileService, MimeFileService>();
+        services.AddTransient<IMimeStorageService, MimeStorageService>();
 
         services.AddTransient<ICalendarService, CalendarService>();
         services.AddTransient<IMailService, MailService>();