diff --git a/res/values/arrays.xml b/res/values/arrays.xml
index 68b88c018..e6cde687e 100644
--- a/res/values/arrays.xml
+++ b/res/values/arrays.xml
@@ -112,6 +112,9 @@
         <item>@string/account_settings_autodownload_message_size_512</item>
         <item>@string/account_settings_autodownload_message_size_1024</item>
         <item>@string/account_settings_autodownload_message_size_2048</item>
+        <item>@string/account_settings_autodownload_message_size_5120</item>
+        <item>@string/account_settings_autodownload_message_size_10240</item>
+        <item>@string/account_settings_autodownload_message_size_any</item>
     </string-array>
 
     <string-array name="account_settings_autodownload_message_size_values">
@@ -127,6 +130,9 @@
         <item>524288</item>
         <item>1048576</item>
         <item>2097152</item>
+        <item>5242880</item>
+        <item>10485760</item>
+        <item>0</item>
     </string-array>
 
     <string-array name="account_settings_folder_display_mode_entries">
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 710bf894a..243e6d3d8 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -617,6 +617,8 @@ Welcome to K-9 Mail setup.  K-9 is an open source mail client for Android origin
     <string name="account_settings_autodownload_message_size_512">512Kb</string>
     <string name="account_settings_autodownload_message_size_1024">1Mb</string>
     <string name="account_settings_autodownload_message_size_2048">2Mb</string>
+    <string name="account_settings_autodownload_message_size_5120">5Mb</string>
+    <string name="account_settings_autodownload_message_size_10240">10Mb</string>
     <string name="account_settings_autodownload_message_size_any">any size (no limit)</string>
 
     <string name="account_settings_message_age_label">Sync messages from</string>
diff --git a/src/com/fsck/k9/controller/MessagingController.java b/src/com/fsck/k9/controller/MessagingController.java
index 079b72812..028ebfcd3 100644
--- a/src/com/fsck/k9/controller/MessagingController.java
+++ b/src/com/fsck/k9/controller/MessagingController.java
@@ -1441,7 +1441,8 @@ public class MessagingController implements Runnable {
                         return;
                     }
 
-                    if (message.getSize() > account.getMaximumAutoDownloadMessageSize()) {
+                    if (account.getMaximumAutoDownloadMessageSize() > 0 &&
+                    message.getSize() > account.getMaximumAutoDownloadMessageSize()) {
                         largeMessages.add(message);
                     } else {
                         smallMessages.add(message);
@@ -1674,8 +1675,11 @@ public class MessagingController implements Runnable {
                      * the account's autodownload size limit, otherwise mark as only a partial
                      * download.  This will prevent the system from downloading the same message
                      * twice.
+                     *
+                     * If there is no limit on autodownload size, that's the same as the message
+                     * being smaller than the max size
                      */
-                    if (message.getSize() < account.getMaximumAutoDownloadMessageSize()) {
+                    if (account.getMaximumAutoDownloadMessageSize() == 0 || message.getSize() < account.getMaximumAutoDownloadMessageSize()) {
                         localMessage.setFlag(Flag.X_DOWNLOADED_FULL, true);
                     } else {
                         // Set a flag indicating that the message has been partially downloaded and
diff --git a/src/com/fsck/k9/mail/store/ImapStore.java b/src/com/fsck/k9/mail/store/ImapStore.java
index b639a11f2..1ee09fc75 100644
--- a/src/com/fsck/k9/mail/store/ImapStore.java
+++ b/src/com/fsck/k9/mail/store/ImapStore.java
@@ -1110,7 +1110,12 @@ public class ImapStore extends Store {
                 fetchFields.add("BODYSTRUCTURE");
             }
             if (fp.contains(FetchProfile.Item.BODY_SANE)) {
-                fetchFields.add(String.format("BODY.PEEK[]<0.%d>", mAccount.getMaximumAutoDownloadMessageSize()));
+                // If the user wants to download unlimited-size messages, don't go only for the truncated body
+                if (mAccount.getMaximumAutoDownloadMessageSize() > 0) {
+                    fetchFields.add(String.format("BODY.PEEK[]<0.%d>", mAccount.getMaximumAutoDownloadMessageSize()));
+                } else {
+                    fetchFields.add("BODY.PEEK[]");
+                }
             }
             if (fp.contains(FetchProfile.Item.BODY)) {
                 fetchFields.add("BODY.PEEK[]");
diff --git a/src/com/fsck/k9/mail/store/Pop3Store.java b/src/com/fsck/k9/mail/store/Pop3Store.java
index a307c8484..f6b8f1063 100644
--- a/src/com/fsck/k9/mail/store/Pop3Store.java
+++ b/src/com/fsck/k9/mail/store/Pop3Store.java
@@ -582,8 +582,12 @@ public class Pop3Store extends Store {
                          * To convert the suggested download size we take the size
                          * divided by the maximum line size (76).
                          */
-                        fetchBody(pop3Message,
-                                  (mAccount.getMaximumAutoDownloadMessageSize() / 76));
+                        if (mAccount.getMaximumAutoDownloadMessageSize() > 0) {
+                            fetchBody(pop3Message,
+                                      (mAccount.getMaximumAutoDownloadMessageSize() / 76));
+                        } else {
+                            fetchBody(pop3Message, -1);
+                        }
                     } else if (fp.contains(FetchProfile.Item.STRUCTURE)) {
                         /*
                          * If the user is requesting STRUCTURE we are required to set the body
diff --git a/src/com/fsck/k9/mail/store/WebDavStore.java b/src/com/fsck/k9/mail/store/WebDavStore.java
index 81a498f25..dfd3d9155 100644
--- a/src/com/fsck/k9/mail/store/WebDavStore.java
+++ b/src/com/fsck/k9/mail/store/WebDavStore.java
@@ -1411,7 +1411,11 @@ public class WebDavStore extends Store {
             }
 
             if (fp.contains(FetchProfile.Item.BODY_SANE)) {
-                fetchMessages(messages, listener, (mAccount.getMaximumAutoDownloadMessageSize() / 76));
+                if (mAccount.getMaximumAutoDownloadMessageSize() > 0) {
+                    fetchMessages(messages, listener, (mAccount.getMaximumAutoDownloadMessageSize() / 76));
+                } else {
+                    fetchMessages(messages, listener, -1);
+                }
             }
             if (fp.contains(FetchProfile.Item.BODY)) {
                 fetchMessages(messages, listener, -1);