If you spot an obvious phishing or even just a suspicious email then, rather than opening it, (and NEVER click on any links in the email) you could forward it to the appropriate address.
These are a few I've collected over the years. The first is a general reporting site while the rest are only interested in their own spoof messages.
Mike
General financial phishing scams reportphishing@apwg.org
Amazon phishing stop-spoofing@amazon.com
Apple phishing abuse@me.com spam@me.com
BOS Phishing security@bankofscotland.co.uk
Cahoot Phishing phishing@santander.co.uk
Co-op Bank ihaveseenascam@co-operativebank.co.uk
Egg Phishing spoof@egg.com
skype abuse@skype.net.
Facebook Spam phish@spamreport.facebook.com
FedEx Phishing abuse@fedex.com
MBNA Phishing emailfraud@mbna.com
tescobank.com phishing@tescobank.com
HSBC phishing@hsbc.com
barclays.co.uk internetsecurity@barclays.co.uk
Littlewoods phishing customersecurity@shopdirect.com
Nationwide phishing phishing@nationwide.co.uk
natwest.com phishing@natwest.com
rbs.co.uk phishing@rbs.co.uk
northernrock.co.uk report.phishing@northernrock.co.uk
Skype Phishing abuse@skype.net
Smile phishing scam ive_seen_a_scam@smile.co.uk
ebay.co.uk spoof@ebay.co.uk
paypal.com spoof@paypal.com
Vodafone phishing phishing@vodafone.co.uk
Yorkshire BS phishing phishing@emis.ybs.co.uk
HMRC phishing phishing@hmrc.gsi.gov.uk
Halifax phishing (Report as header) onlineemailinvestigations@hbosplc.com