Thanks to steabert on stackexchange for posting this helpful tip!
In Gmail, simply search for “size:xxxxxxxx“
This undocumented search parameter will help you find messages larger than the size you searched for.
The search parameters are in bytes, so 10485760 = 10MB or 52428800 = 50 MB, and so on.
EDIT: As of November 15th, Google has officially released support for this feature
“To find emails larger than 5MB, you can search for size:5m or larger:5m“
If you’re getting this problem,it’s Google’s Fault, and not the Windows 7 / Windows 8 Phone’s.
Go to the following URL, put your password in and enter the captcha. This will solve the problem and let you use your Gmail account on your Windows Phone.
https://www.google.com/accounts/DisplayUnlockCaptcha
It seems to disable some captcha security setting on your Gmail Account. Use at your own risk, I don’t know what else it does.
So Google hasn’t ironed all the kinks out yet for their help and support regarding the newly rolled out HTML Signatures, as this simple fix alluded the Google Support team for a week.
If you’re having trouble finding out why your GMail won’t show an HTML signature, try this:
Switch the Email Composer to Rich Formatting, instead of Plain Text.
1. Click compose mail
2. Click on “Rich formatting” (under Subject and just over the message textbox)
3. Go back to settings (no actual message has to be created, this is just to change that setting).
Why this isn’t simpler in the settings, I don’t know.