Integrate CSS with yagmail python

Question

I am trying to automate a report and send it by mail daily. I would like to have images / graphs embedded in my mail.

My program currently generates graphs and saves them on my Destok so I can then join them to my mail with yagmail. I pass a list of HTML lines as strings in a "body" variable to generate the mail. I then extend my HTML body to scale it for every studied subject automatically.

Issue : the graphs do not show on mobile. I think a good option would be to add something in my HTML mail body like CSS : img {max-height : 100 %;} but can't figure how to do it with my current method.

I tried to use a mail service provider (mailjet) but could not customize my mail as I wished (ex: loop through text and images).

Hope someone can help.

My mail code :

#receivers as a list
receivers = ["abcdef@gmail.com", 
    "ghijkl@gmail.com"
    ]

#date
now=datetime.now()  #record current moment
date_mail=str(now.strftime('%d%m%Y'))+ " (ddmmYYYY)"    #format as daymonthyear + add some text + all as text => will be in mail header

#Identification
yagmail.register("my_sender_mail@gmail.com", "password_me")    #register to yagmail / gmail adress + application password
yag = yagmail.SMTP("my_sender_mail@gmail.com")                      #define mail

#mail body
body = ["<p>Hello,</p>",  #will be merged for every analysis / is a list !
"<p>Please find below your daily ......</p>",
"<p>Our method combines different strategies to ..... </p>",
"<p>If we are not confident enough accross multiple methods ....</p>",
"<p>If a method yields poor result it will not be displayed on the graphs.</p>",
"<br>",    #input a line
"<p>If the graphs do not show properly please allow your mailbox to ""download"" images for this sender.</p>",
"<p>Please do not hesitate to contact us to ....</p>",
"<br>",
"<p><b>"+str(tickers[0])+" </b></p>",                                 # first ticker in the body
"<p>Daily signal: "+ mail_decision[0] +" </p>",                       # first decision for the ticker
"<p>Graph :</p>",
"""<img src="C://Users//tangu//OneDrive//Bureau//image_"""+str(0)+"""_complete.png" width="700" height="450">""",   #embed main graph for the whole period, set width (issue!) and height
"""<img src="C://Users//tangu//OneDrive//Bureau//image_"""+str(0)+"""_reduced.png" width="700" height="450">"""     #embed the reduced graph for a short term view, set width (issue!) and height
]

for i in range(1,len(tickers)):                         #extend the body for every strategy
    body_to_app=["<p><b>"+str(tickers[i])+" </b></p>",  #ticker in the body
    "<p>Daily signal: "+ mail_decision[i] +" </p>",     #decision for the ticker
    "<p>Graph :</p>",
    """<img src="C://Users//tangu//OneDrive//Bureau//image_"""+str(i)+"""_complete.png" width="700" height="450">""",   #embed main graph for the whole period, set width (issue!) and height
    """<img src="C://Users//tangu//OneDrive//Bureau//image_"""+str(i)+"""_reduced.png" width="700" height="450">""",    #embed the reduced graph for a short term view, set width (issue!) and height
    ]
    body.extend(body_to_app)                            #extend (/"merge") the list

#add best regards
body.extend(["<p>Best Regards,<p>"])

#loop through recievers
for receiver in receivers:                                  #for element in recievers
    #send the mail
    yag.send(
        to=receiver,
        subject="Subject at date :  _ "+str(date_mail),
        contents=body
    )