Can't share photos by email

Hello. Ever since the new 'photos' app came in I have been unable to share photos by email on my imac. I can do it on my iphone/ipad but not on the big computer. I use gmail in google chrome. On the shre options it is ticked but greyed out. I've checked that my account is enabled on the 'mail' app- athough I don't use the app, as I dont like it, I use webmail,. I used to be able to email photos from the horrible mail app, but now not even that option comes up. I would really like to be able to select gmail as I can on my phone Can anyone help?