Improve export diagnostics and splash

MailExporter.spec

@@ -17,6 +17,7 @@ a = Analysis(
     hiddenimports=[
         "pythoncom",
         "pywintypes",
+        "win32timezone",
         "win32com",
         "win32com.client",
     ],
@@ -58,8 +59,20 @@ a = Analysis(
 
 pyz = PYZ(a.pure)
 
+splash = Splash(
+    str(project_dir / "splash.png"),
+    binaries=a.binaries,
+    datas=a.datas,
+    text_pos=(220, 300),
+    text_size=14,
+    text_color="black",
+    text_default="Avvio MailExporter...",
+    always_on_top=True,
+)
+
 exe = EXE(
     pyz,
+    splash,
     a.scripts,
     [],
     exclude_binaries=True,
@@ -78,6 +91,7 @@ exe = EXE(
 
 coll = COLLECT(
     exe,
+    splash.binaries,
     a.binaries,
     a.datas,
     strip=False,