Trying to look for a file with bunch of test1@test.com, test2@test2.com and etc.
for line in fh:
if not line.startswith('From: ') : continue
email_line = line.split()
domain = email_line[1].split('@')[1] the right hand side (domain)
#print domain
Line # 4: double split, first split at the From, second split at the @ the pick [1] which is the left side of the string index.