Linear backoff: 1 and 5 min

FAQ.md

@@ -3448,10 +3448,11 @@ FairEmail will retry one time after waiting 8 seconds while keeping the device a
 If this fails, FairEmail will schedule an alarm to retry after 5, 15, 30 and eventually every 60 minutes and let the device sleep (=no battery usage).
 
 By temporarily enabling debug mode in the miscellaneous settings, you can disable this logarithmic back-off scheme (since version 1.1855).
-This will result in using a linear back-off scheme, which means that after each successive failure the waiting time will be increased by 1 minute up to 60 minutes.
+This will result in using a linear back-off scheme, which means that after each successive failure the waiting time will be
+increased by 1 minute the first 5 minutes and thereafter by 5 minutes up to 60 minutes.
 
 Note that [Android doze mode](https://developer.android.com/training/monitoring-device-state/doze-standby)
-does not allow to wake the device earlier than after 15 minutes when doze mode is enabled.
+does not allow to wake the device earlier than after 15 minutes when doze mode is active.
 
 *Force sync* in the three-dots menu of the unified inbox can be used to let FairEmail attempt to reconnect without waiting.
 

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -2391,7 +2391,7 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                         }
                     } else {
                         // Linear back-off
-                        int b = backoff + 60;
+                        int b = backoff + (backoff < CONNECT_BACKOFF_INTERMEDIATE * 60 ? 60 : 5 * 60);
                         if (b > CONNECT_BACKOFF_ALARM_MAX * 60)
                             b = CONNECT_BACKOFF_ALARM_MAX * 60;
                         state.setBackoff(b);