We just received this tip email from someone whose battery was draining much quicker than it should:
Worth checking out if you're having a similar problem
I was recently experiencing problems with short battery life on my HTC Inspire. I would drain the battery in a few hours. I found an e-mail in my Out Box that the operating system was constantly attempting to send but was too large. After removing the e-mail I am back to 12 hours on battery with 80% charge remaining.
Worth checking out if you're having a similar problem