diff --git a/app/src/main/java/eu/faircode/email/FragmentAccount.java b/app/src/main/java/eu/faircode/email/FragmentAccount.java
index 98a12b4c..f53f65ee 100644
--- a/app/src/main/java/eu/faircode/email/FragmentAccount.java
+++ b/app/src/main/java/eu/faircode/email/FragmentAccount.java
@@ -49,7 +49,6 @@ import com.sun.mail.imap.IMAPStore;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Objects;
 
 import javax.mail.Folder;
 import javax.mail.MessagingException;
@@ -191,11 +190,19 @@ public class FragmentAccount extends FragmentEx {
                 String host = args.getString("host");
                 String port = args.getString("port");
                 String user = args.getString("user");
+                String password = args.getString("password");
+
+                if (TextUtils.isEmpty(host))
+                    throw new Throwable(getContext().getString(R.string.title_no_host));
+                if (TextUtils.isEmpty(port))
+                    throw new Throwable(getContext().getString(R.string.title_no_port));
+                if (TextUtils.isEmpty(user))
+                    throw new Throwable(getContext().getString(R.string.title_no_user));
+                if (TextUtils.isEmpty(password))
+                    throw new Throwable(getContext().getString(R.string.title_no_password));
 
                 if (TextUtils.isEmpty(name))
                     name = host + "/" + user;
-                if (TextUtils.isEmpty(port))
-                    port = "0";
 
                 DB db = DB.getInstance(getContext());
                 EntityAccount account = db.account().getAccount(args.getLong("id"));
@@ -206,7 +213,7 @@ public class FragmentAccount extends FragmentEx {
                 account.host = host;
                 account.port = Integer.parseInt(port);
                 account.user = user;
-                account.password = Objects.requireNonNull(args.getString("password"));
+                account.password = password;
                 account.synchronize = args.getBoolean("synchronize");
                 account.primary = (account.synchronize && args.getBoolean("primary"));
 
diff --git a/app/src/main/java/eu/faircode/email/FragmentIdentity.java b/app/src/main/java/eu/faircode/email/FragmentIdentity.java
index b19227bd..07b5fff2 100644
--- a/app/src/main/java/eu/faircode/email/FragmentIdentity.java
+++ b/app/src/main/java/eu/faircode/email/FragmentIdentity.java
@@ -215,11 +215,20 @@ public class FragmentIdentity extends FragmentEx {
                 String host = args.getString("host");
                 boolean starttls = args.getBoolean("starttls");
                 String port = args.getString("port");
+                String user = args.getString("user");
+                String password = args.getString("password");
+
+                if (TextUtils.isEmpty(host))
+                    throw new Throwable(getContext().getString(R.string.title_no_host));
+                if (TextUtils.isEmpty(port))
+                    throw new Throwable(getContext().getString(R.string.title_no_port));
+                if (TextUtils.isEmpty(user))
+                    throw new Throwable(getContext().getString(R.string.title_no_user));
+                if (TextUtils.isEmpty(password))
+                    throw new Throwable(getContext().getString(R.string.title_no_password));
 
                 if (TextUtils.isEmpty(replyto))
                     replyto = null;
-                if (TextUtils.isEmpty(port))
-                    port = "0";
 
                 DB db = DB.getInstance(getContext());
                 EntityIdentity identity = db.identity().getIdentity(id);
@@ -232,8 +241,8 @@ public class FragmentIdentity extends FragmentEx {
                 identity.host = Objects.requireNonNull(host);
                 identity.port = Integer.parseInt(port);
                 identity.starttls = starttls;
-                identity.user = Objects.requireNonNull(args.getString("user"));
-                identity.password = Objects.requireNonNull(args.getString("password"));
+                identity.user = user;
+                identity.password = password;
                 identity.synchronize = args.getBoolean("synchronize");
                 identity.primary = (identity.synchronize && args.getBoolean("primary"));
 
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 9aa6cef1..6ebb5a45 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -62,7 +62,10 @@
     <string name="title_primary_identity">Primary (default identity)</string>
     <string name="title_no_name">Name mandatory</string>
     <string name="title_no_email">Email address mandatory</string>
-    <string name="title_no_idle">IDLE not supported</string>
+    <string name="title_no_host">Host name missing</string>
+    <string name="title_no_port">Port number missing</string>
+    <string name="title_no_user">User name missing</string>
+    <string name="title_no_password">Password missing</string>
     <string name="title_local_drafts">Local drafts</string>
 
     <string name="title_folder_unseen">%1$s (%2$d/%3$d)</string>