Check to Make Sure It's a Mistake
Make sure you clicked the right link. Use compare documents to ensure there are no changes (or use a checksum, like you did). Before making a request and causing conclusion, do your due diligence to save some headaches.
The Issue with E-mail
E-mail is a really really messy medium. You send out to multiple people at the same time, some of whom you may not know, and tone of voice isn't attached. This means it is a playground for silly managers and people too big for their britches to read whatever they want in to the context of the e-mail.
For that reason I suggest a quick IM or phone call (at a minimally-intrusive time, like first thing in the morning, or just after lunch). That allows you to speak directly to the person, make it easy for them to fix it immediately (rather than become another request in the inbox), and allow your tone of voice convey information lost in an e-mail.
If you do send an e-mail, I highly recommend sending it just to the person who sent the file. Remove all the CC's, and just send a quick simple e-mail like:
Hey John, I double-checked the file you sent yesterday, but it hasn't been updated since last time. When you get a chance, could you give it a look and update if needed? Thanks.
The keys are:
- Explain that you already checked
- Provide them with a clear action
- Don't include any negative language assigning blame
E-mail by nature feels "serious" so keeping it short can be a good strategy to mitigate the seriousness. If you format the same above e-mail in incredibly formal fashion, it feels totally different:
I double-checked the file you sent yesterday, but it hasn't been updated since last time.
When you get a chance, could you give it a look and update if needed?
Thanks in advance,