Someone emailed and offered me a job in UK..how will I know if this is a scam or not?

i replied to his email and expressed interest of applying..but i am a bit apprehensive..here are some parts of his email - "Hello How are you? Thanks for the reply to my job offer and the interest in my family.I would like to see your Curriculum Vitae (CV)and also your scanned pport copy.Truly i need a foreign Nanny,i know that there are a lot of Nannies in the UK here but its just that i need a Nanny from outside,that is caring,loving,motherly carefree and well determined,that can take good care of my kids for me but with the recommendation from you and that is the more reason I may need your services,hopefully you will be my kid's Nanny and do according to your words. I reside in Lambert,London and do not get worried about any doents(work Permit and Visa),a travel agency here in the UK will handle that for you as per your visa just scan&send the copy of your international pport and CV through email to them,they will apply for visa on your behalf in the UK Home Office and when the visa is ready the UK Emby in your country will call on you so that they can endorse the visa on your original pport.If you have any other traveling agency you could also use that. I love my kids so much and would not toy with them.They are the apple of my eyes.I work because of them and am willing to pay any amount to give them the best in the world.You would be needing to settle the Visa Procurement yourself because i paid for 2 Nannies in the past few months which they did not turn up but went somewhere else after their visa was approved and that is why i vowed that any Nanny that i will employ will make half of expenses by himself/herself.Hope you understand how i mean.I need a very serious person and the job is available right now.Also,i use to have a Nanny and she spent 2 years with us,but she got married and relocated to the United states,so i need a replacement ASAP. Your duties are as follows: 1-Supervise breakfast with the children in the morning and get them off to school (Collect my 2KIDS of ages 6yrs old and 4year and half on from school at 3..40pm.) 2-Some Housework/washing/ironing as required on a daily basis 3-Supervise homework, music practice and fun activities or take children to after school activities. 4-Prepare and cook an evening meal for everyone at about 6.30-6.45 Up to two evenings child minding per week. 5-Weekends and Bank holidays would be free that there will not be much duties to carry out. 6-Occasional weekend work would be offered by prior negotiation. I normally leave for work at 7.00am and get back at around 6.30pm although some flexibility is useful. I am offering a live-in position with full board (we eat well in this house!) 1-Separate Toilet and Bathroom. 2-TV,different types of video machines. 3-Personal computer already Internet on. e.t.c for you and i will make sure everything goes on well with you, with my kids. Don't worry about the United Kingdom,it's a nice place to stay and i hope you will enjoy staying here with my family and you will have the access to internet, In fact i have a personal PC at home for myself but my kids usually play games on their own PC, i will get you a computer to start using for your own use.All expenses made by you will be refunded immediately you get here.If you would be using the travel agency i would be recommending my traveling agent to you."