diff --git a/app/src/main/java/eu/faircode/email/FragmentIdentity.java b/app/src/main/java/eu/faircode/email/FragmentIdentity.java
index 7ef5c17ed5..cae792de44 100644
--- a/app/src/main/java/eu/faircode/email/FragmentIdentity.java
+++ b/app/src/main/java/eu/faircode/email/FragmentIdentity.java
@@ -401,8 +401,11 @@ public class FragmentIdentity extends FragmentEx {
                         if (TextUtils.isEmpty(password) && !insecure)
                             throw new IllegalArgumentException(getContext().getString(R.string.title_no_password));
 
+                        email = email.toLowerCase();
                         if (TextUtils.isEmpty(replyto))
                             replyto = null;
+                        else
+                            replyto = replyto.toLowerCase();
                         if (Color.TRANSPARENT == color)
                             color = null;
 
diff --git a/app/src/main/java/eu/faircode/email/ServiceSynchronize.java b/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
index ea8941c2ef..e3e5138093 100644
--- a/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
+++ b/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
@@ -1874,9 +1874,12 @@ public class ServiceSynchronize extends LifecycleService {
             EntityIdentity identity = null;
             if (tos != null && tos.length > 0) {
                 String to = ((InternetAddress) tos[0]).getAddress();
-                identity = db.identity().getIdentity(folder.account, to);
-                if (identity == null)
-                    identity = db.identity().getIdentity(folder.account, Helper.canonicalAddress(to));
+                if (!TextUtils.isEmpty(to)) {
+                    to = to.toLowerCase();
+                    identity = db.identity().getIdentity(folder.account, to);
+                    if (identity == null)
+                        identity = db.identity().getIdentity(folder.account, Helper.canonicalAddress(to));
+                }
             }
 
             message = new EntityMessage();