For email I'd send jpeg ,they can be made smaller(file size) than Bmp and hold quality better than gif.
http://www.scantips.com/basics09.html
Instead of "exporting" try "save as" when sending it are you "attaching" or "inserting" ,I would suggest attaching.I've had probs with pics people have sent me if they send them via IE and I use Netscape Mail ,its to do with the way they are encaoded.
In Irfanview :
To Scan FILE>acquire(you may have select twain source)
To compress file size
Tutorial
To email Options>send image by email (you may need to set it up ,if you need any settings they should be in your default mail programs settings i.e. smtp settings.
[This message has been edited by wonderinguy34 (edited 07-15-2001).]