Welcome Email template is different

I have set up my custom email provider and would like to adjust a bit for the Welcome Email style. However…

  1. Just like previous discussions, the template is different after enabling custom email provider. Is it possible to get the Welcome Email template script with full CSS for reference?
  1. I tried to use {{ user.picture }} variable in my welcome email template, and found that the image can be displayed normally in Outlook, but the image can’t show in Gmail.

Here is the code:

                          <img 
                            src= {{ user.picture }}
                            width ="50"
                            alt="your picture"
                          />