You'd be better copying them to a memory stick than emailing them. Even if your IT dept allows you to send big photos they wouldn't be happy about it.
Scanning loads of photos is quite a pain. Some scanners, the more expensive ones come with a negative holder so you can scan a few of them at a time.
For a lot of photos it might be worth paying somewhere to do it, as they often have a feeder and it doesn't take them much time at all.
For a digital photoframe you don't need high quality scans and it would be a lot quicker and you'll fit more in it, if you scan them at a lower resolution. Try to match the resolution of the photoframe. If you are planning to archive the scans for the future, then you'd be better scanning them in a higher res.