I am experiencing the exact same issue as you, and so is my coworker who also is on an EVO. Kind of surprised the forums are not blowing up about this, and hope there is a quick solution.

 

I try to forward a message in gmail yesterday. It still sitting at sending even I had manually syn many time. I have to log on to my PC to forward the message.

 

Go into manage applications on the gmail, wipe data and cache and then reboot phone

 

It's not just the Evo. My Epic, my wife's Evo and the old Hero are all doing the same thing and have been for the past 2 days.

Clearing data/cache hasn't helped either of us.

 

Flashed 2 different roms the last day and never had an issue, sense and aosp roms, weird

 

It seems to be hit and miss. One minute it's fine and the next it's not working again.

Who knows!

 

I have been having hit or miss issues with gmail's syncing for about 3 weeks now. it eventually goes away...but may come back a week later.

it had been working pretty well for the past week...then I noticed it back again today.

last time I installed the HTC mail apk back onto my phone to have a backup and it appears to work fine even when the gmail app doesn't sync..

 

Google not syncing Email. Not notifications nothing - Google Mobile Help

 

no fixed here

 

Same issue for the last 2 days, also getting "Force Close" alerts sometimes when I try to send email. I've tried the clear data, cache, and reboot, still issues. Hopefully they send a fix for this, trying to check mail away from the pc is a pain now.

 

guys in the meantime try the stock htc mail app. it appears to work fine. Over the past month the issue has come and go. some days it will work wonderfully.....others not at all.