Ma Chere Amour

I get this email, "Cher(e),"
Now I know enough about French tell you this is a opening like saying Mr(s), but "Cher" I find out is dear, so we would say, Dear Mr.(s), meaning Mr or Mrs. They can do the gender in one word, kinda like "I can name that song in two notes" . So anyway, I am wondering now about that word.
And speaking of naming songs, "Ma chere amour" this is what has me messed up. I wondered how that was spelled, surely not as above since you can't pronounce the last e in french.
So I have this discussion with my step daughter." Cher " it does mean dear, and they use it as a term of affection also. So why have I learned the a word "Chereee"? Well she tells me you can pronounce the last E in songs and poetry. Songs and poetry pass along so much language, no wonder I'm messed up.