8000 Records In Over 12 Minutes?

I have the following SQL select query:

Code:
SELECT
inbound_emails.inbound_email_id,
inbound_emails.campaign_id,
campaign_header.campaign_name,
customers.customer_name,
inbound_emails.date_received,

[Code] ....

Without any indexes (other than PK's) this query would take 1min 21 secs to return all 8500 records.

I wasn't satisfied with that so I added indexes to the tables.

Indexes are;

inbound_emails:

PK: inbound_email_id
1. campaign_id (non-unique, non-clustered)
2. email_from (non-unique, non-clustered)
3. email_to (non-unique, non-clustered)

campaign_header:

PK: campaign_id
1. campaign_name (unique, non-clustered)

customers:
PK: customer_id
1. customer_name (unique, non-clustered)

contracts:
PK: contract_id
1. contract_name (unique, non-clustered)
2. customer_id (non-unique, non-clustered)

Have I made a hash of the indexes? Or is the query statement badly written? What is a reasonable amount of time to expect to retrieve 8500 records?

I think email_from and email_to on inbound_emails is the main culprit, but I don't understand why?