Please Help me to fix this Mongo Query

help
1 
return Messages.find({
        $or: [{ $and: [{ senderId: userId }, { recieverId: recId }] }, { $and: [{ senderId: recId }, { recieverId: userId }] }],
    }, { limit: 1, sort: { sentAt: -1 } });
2

looks good. is it not showing an error?
if there is not result then the error is in the logic itself.

3

Maybe spelling of variables? (receiver was misspelled). Try running meteor mongo and see if your query works there, cut it down to pieces until you identify the issue.

4 
return Messages.find({
        $or: [ { senderId: userId, receiverId: recId }, { senderId: recId, receiverId: userId }] 
    }, { limit: 1, sort: { sentAt: -1 } });