I think it might be helpful if you gave some more details...
If you want to send one and the same email to multiple recipients you just add the addresses in the to and cc fields - using Gmail I do not have any problem with that.
If you write several emails while being offline they are being stored in the outbox once you pressed send. When you get back online and open your native email app they should get out just like that....
So, what is the problem?