diff -urp webkitgtk-2.51.90.orig/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp webkitgtk-2.51.90/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp
--- webkitgtk-2.51.90.orig/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp	2026-01-29 13:50:54.092002720 -0600
+++ webkitgtk-2.51.90/Source/WebKit/UIProcess/API/glib/WebKitWebContext.cpp	2026-01-29 13:57:43.113956749 -0600
@@ -444,6 +444,12 @@ static void webkitWebContextConstructed(
     configuration->setUsesWebProcessCache(true);
 #if PLATFORM(GTK) && !USE(GTK4)
     configuration->setProcessSwapsOnNavigation(priv->psonEnabled);
+    if (!priv->psonEnabled) {
+        const char* prgname = g_get_prgname();
+        if (!g_strcmp0(prgname, "evolution") || !g_strcmp0(prgname, "geary")) {
+            configuration->setUsesSingleWebProcess(true);
+        }
+    }
 #if USE(CAIRO)
     configuration->setUseSystemAppearanceForScrollbars(priv->useSystemAppearanceForScrollbars);
 #endif