The answer to the first question, "How many emails did I send during a given timeframe?", can be answered as shown here:

print(dfs.index.min().strftime('%a, %d %b %Y %I:%M %p'))
print(dfs.index.max().strftime('%a, %d %b %Y %I:%M %p'))

print(dfs['label'].value_counts())

The output of the preceding code is given here:

Tue, 24 May 2011 11:04 AM
Fri, 20 Sep 2019 03:04 PM
inbox 32952
sent 4602
Name: label, dtype: int64

If you analyze the output, you'll see that we analyzed emails from Tue, 24 May 2011 11:04 AM, to Fri, 20 Sep 2019 03:04 PM. There were 32,952 emails received and 4,602 emails sent during this timeframe. That is a pretty good insight, right? Now, let's jump into the next question.