Appointments+ strange signs in confirmation emails iPhone mail


I have some troubles with Appointments+ confirmation mails opened in iPhone Mail app.

Its strange because with gmail or airmail i see it perfectly.

Characters problematics are: á é í ó ú and signs like ¡

Problems too with url displayed

I add a screenshot with airmail version and iphone version of the same message:


Can someone help my with this little CSS problem in the same page:

Thanks to all