import re
full_name_list=['John Doe', 'James Henry', 'Jane Doe']
source = r" John Doe is part of our team and here is his email: johndoe@something.com. James Henry is also part of our team and here his email: jameshenry@something.com. Jane Doe is the team manager and you can contact her at that address: janedoe@something.com"
for name in full_name_list:
    # full name followed by the email
    name_email = re.search(r'\b' + name+r'\b.*?([\w.-]+@[\w.-]+\.w+)', source)
    if name_email:
    	print( 'Email before "{}" keyword: {}'.format(name, name_email.group(1)) )
    # email followed by full name
    email_name = re.search(r'\b([\w.-]+@[\w.-]+\.\w+)(?:(?![\w.-]+@[\w.-]+\.\w).)*?\b'+name+r'\b', source, re.S)
    if email_name:
    	print( 'Email after "{}" keyword: {}'.format(name, email_name.group(1)) )